### Program for 2017 11th European Conference on Antennas and Propagation (EUCAP)

Time Oral Sessions: Auditorium Bordeaux Oral Sessions: Auditorium Havane Oral Sessions: Room 341 Oral Sessions: Room 342A Oral Sessions: Room 342B Oral Sessions: Room 343 Oral Sessions: Room 351 Oral Sessions: Room 352A Oral Sessions: Room 352B Oral Sessions: Room 353 Oral Sessions: Room 362/363 Poster Sessions: Corridor Neuilly Poster Sessions: Corridor Paris Poster Sessions: Corridor Top WG Meetings & Workshops: Room 313/314 WG Meetings & WorkShops: Room 315

## Monday, March 20

09:00-10:00 Opening Session
10:00-10:40 IK_01 Invited Keynote 1
11:10-12:30 IK_02 Invited Keynote 2&3
14:00-18:30 Sp_P01 Tropospheric Propagation for Space Applications I CS31 New Trends in Reflectarrays and Transmitarrays CS19 High-Data Rate Wireless Connectivity for Smart Rail Mobility C_P01 Millimeter Wave Radio Channels I B_A01 Antennas for Biomedical Applications H_A02 Mm-Wave Antennas for High Data Rate I CS20 In Memory of Prof. Per Simon Kildal (Dedicated session) R_M01 RCS Measurements CS24 Measurements and Simulations in Channel Modelling in Wireless Body Area Networks (COST CA15104 IRACON) MT_A01 Integral Equations CS01 A Century After Tesla: How Far Have We Come With Wireless Power Transfer ?
16:30-18:30 CS08 Advances on Transformation Electromagnetics Based Antennas C_M02 Measurement Topics B_P03 Biological Propagation Measurements CS23 Massive MIMO Antenna Technologies and Interference Mitigation Techniques for 5G Networks in the Frequency Bands above 6 GHz R_A02 Antennas for Imaging L_A04 Wireless Power Transmission and Harvesting I MT_A02 Computation Techniques CS22 Innovative Antennas for TT&C and PDTM Satellite Links       WG_01 Propagation

## Tuesday, March 21

08:40-12:30   CS02 Additive Manufacturing for Antenna and RF Components W_A01 Adaptive & Reconfigurable Antennas for Wireless Networks C_M01 MIMO measurements CS05 Advances in Electromagnetic Diagnostics and Biomedical Sensors CS25 Mm- and THz- wave Propagation Measurements and Modelling for Ultra-high Data Rate Communications (COST CA15104 IRACON) CS29 New Antenna Systems Involving Application of Metamaterials and Metasurfaces (IET) R_A01 Mm-Wave Radar Antennas CS45 Smart Beamforming in Far-Field Wireless Power Transmission CS04 Advanced Statistical Methods and Tools in Applied Electromagnetism F_A04 Submillimeter-wave & Terahertz antenna       IWS_01: How to design a matching circuit that matches with the measurements?
10:50-12:30   W_A02 Arrays Antenna for Wireless Networks R_P04 RCS Models L_A02 Wireless Power Transmission and Harvesting II F_A05 Adaptive & Reconfigurable Antennas for Future Applications       WG_02 Small Antennas IWS_05: ANSYS Workshop: Antenna Placement and Coupling
13:30-16:20                       Poster_01 Poster_02   WG_03 Measurement EurAAP WG SWS_01: Advances in Commercial Electromagnetic Simulation Tools
15:00-16:20 Inv_01 Invited Session 1 Inv_02 Invited Session 2                         WG_03 AMTA Europe Meeting
16:50-18:30 Sp_A01 Frequency & Polarization Selective Surfaces CS11 Current Challenges in Low Frequency Antenna System Verification W_A04 Mm-Wave Antennas for Wireless Networks C_P05 Time-Varying Radio Channels CS32 OPTIC BIOEM and other approaches for electropulsation in medicine and biology CS47 THz Antennas and Subsystems for High Data Rate Communication Links CS18 Glide Symmetry Surfaces for mm and Sub-mm Lens Antennas R_P01 Radar Imaging CS37 Propagation in Aeronautics CS43 Signal Processing Techniques to Improve Antenna Characterization Procedures (AMTA/EurAAP) CS46 The Alphasat Aldo Paraboni Scientific Experiment: Results and Developments after 3 Years of Operations         IWS_03: New Over-the-Air Measurement Methods and Design Considerations for Millimeter Wave Antenna Arrays

## Wednesday, March 22

08:40-12:30   CS17 From Pioneering Antenna Contributions to Industrial Applications CS44 Small Antennas: From Theory to Practice C_P03 Urban Propagation B_P01 Biomedical Imaging CS48 THz Wireless Communications: from Components to Systems CS27 Mm-wave GAP Waveguide Technology CS13 Electromagnetic Methods for Direct and Inverse Scattering Involving Stratified Media L_A03 MIMO & Smart Antennas CS10 Characteristic Mode Analysis for Platform-Mounted Antenna Design Sp_P02 Tropospheric Propagation for Space Applications II         SWS_05: Revision and Changes to the IEEE 149 Standard on Antenna Measurements (AMTA Workshop)
10:50-12:30   C_P04 Millimeter Wave Radio Channels II B_M01 Biological Measurements L_P01 Localization & Ranging B_P02 Body-Centric Propagation Sp_A05 Antenna-System for Space Applications
13:30-16:20                       Poster_03 Poster_04 Poster_05   SWS_03: Nanotechnology Applications of Antennas and Wireless Sensing
15:00-16:20 Inv_03 Invited Session 3 Inv_04 Invited Session 4                         IWS_04: Efficient simulation of antenna placement on different platforms (Aeronautical, Automotive, Naval,...)
16:50-18:30 Sp_A03 Reflectarrays and Transmitarrays CS21 Innovative Antenna Architectures for Very High Throughput Satellite (VHTS) Systems W_P01 Vehicular channels C_P02 Indoor Propagation CS50 Wireless Sensors for Medical Applications: from Wearables to Implants H_A04 Mm-Wave Antennas for High Data Rate II CS40 Radiation Control Techniques for Small Antennas R_P02 Radar Systems L_A01 Antenna sensors MT_M01 Advances in Test Range Design F_A02 MetaSurfaces I       WG_05 ESoA

## Thursday, March 23

08:40-12:30   CS41 Recent Developments in Antenna Technologies for Emerging Satellite Systems CS30 New Trends in Characteristic Modes Research C_A02 Small and Compact Antennas CS16 European Academic and Industrial Advances in Microwave Medical Technologies (COST TD1301 MiMed) CS26 Mm-wave Antenna Systems for Future Broadband Communication Networks F_A06 Nano Antennas CS15 Emerging Strategies for the Synthesis of Innovative Array-Antenna Architectures L_M02 Near-Field Measurements CS39 Propagation Channels for Wide Sense Vehicle to X Communications CS42 Satellite and Aerospace Antenna Measurements (AMTA/EurAAP)         IWS_02: CST Workshop - Advanced Antenna System Simulation
10:50-12:30   C_A01 Wideband Antennas F_A07 Antenna theory L_M01 MIMO & OTA measurements
13:30-16:20                       Poster_06 Poster_07 Poster_Awards SWS_04: Radiofrequency coils for Magnetic Resonance Imaging SWS_02_I: Frontiers in Propagation and Wireless Channel Modeling
15:00-16:20 Inv_05 Invited Session 5 Inv_06 Invited Session 6
16:50-18:30 Sp_A04 MetaSurfaces for Space Applications CS14 Electronically Scanned SatCom Terminal Antennas: State-of-the-Art and New Developments W_A03 3D Printed Antennas CS36 Practical Applications of Characteristic Mode Theory to Antenna Design CS06 Advances in Microwave Breast Cancer Diagnosis and Treatment (COST TD1301 MiMed) H_A01 Mm-Wave Antennas for High Data Rate III F_P01 Numerical Radio Channel Modeling CS38 Propagation Aspects in Remote Sensing L_A05 Wire & Loop Antennas R_P03 Imaging and Inverse Scattering F_M03 Material Measurements

## Friday, March 24

08:40-11:50 Sp_A02 Reflector & Lenses for Space Applications   F_A03 Antennas for future Applications CS33 OTA Characterization of Antennas and Devices from RIMP to Random-LOS and all in Between CS12 Developments in Electromagnetic Medical Interventions (COST TD1301 MiMed and COST BM1309 EMF-MED) H_A03 Array Antennas for Future Applications CS03 Addressing Radio Frequency Test Challenges in Diverse Environments (AMTA/EurAAP) CS28 Near Field Antenna Measurement Techniques (AMTA/EurAAP) CS09 Antenna for IoT Applications R_A03 Defense and Security Applications CS34 Phased Arrays for Radio Astronomy
10:30-11:50     F_A08 Leaky-Wave Antennas F_P02 Other Propagation Topics F_A01 Metasurfaces II CS49 Wireless Chipless Sensors CS35 Polarimetric Radar Signal Processing and RCS Analysis
12:00-13:00 Closing Ceremony

## Monday, March 20

### Monday, March 20, 09:00 - 10:00

#### Opening Session

Room: Oral Sessions: Auditorium Bordeaux
Chairs: Cyril Mangenot (European Space Agency, The Netherlands), Alain Sibille (Telecom ParisTech, France)

### Monday, March 20, 10:00 - 10:40

#### IK_01 Invited Keynote 1

Room: Oral Sessions: Auditorium Bordeaux
Chair: Cyril Mangenot (European Space Agency, The Netherlands)
10:00 A Whirlwind of Innovation in Space Technology
Jean-Claude Souyris (CNES, France)
This presentation will primarily turn the spotlight on the hot topics of the moment in Space activities: the arrival of new players, mainly from the digital world where young millionaires discover a passion for space and are receptive to the idea that space can be conquered by private entrepreneurs; the emergence of large scale satellite constellations; the enthusiasm for nanosatellites enabling the academic world to nurture its training and research ambition; the growing volumes of satellite data, and the development of space applications fuelled by the spectacular transition to the digital economy. We will then address some of the key technologies for the Space of tomorrow (including those in the field of RF technics, antennas, and propagation), that need to be mastered in order to adapt to the foreseen changes. The talk will finally be illustrated by an example of innovation management in a timeline of 25 years in the field Earth Observation based on RF and antenna techniques (radar altimetry) for ocean observation and water management.

### Monday, March 20, 11:10 - 12:30

#### IK_02 Invited Keynote 2&3

Room: Oral Sessions: Auditorium Bordeaux
Chairs: Anja K. Skrivervik (EPFL, Switzerland), J (Yiannis) Vardaxoglou (Loughborough University, United Kingdom (Great Britain))
11:10 Human-Centric Antennas
Koichi Ito (Chiba University, Japan)
Recently, wearable wireless devices have been widely used in our daily life. Also, implantable wireless devices have been developed and become available for various monitoring as well as identification systems. Unlike conventional wireless devices, wearable or implantable devices are used on or in the human body. In this sense, body-centric wireless communications (BCWCs) have become a very active area of research. On the other hand, radio-frequency or microwave medical devices used for cancer treatment and surgical operation have completely different functions. However, they are used on or in the human body. In terms of antennas installed inside the devices, such medical devices have lots of similarities to BCWCs. To design properly and to make the best use of specific antennas for different wireless devices, it is important to treat them as human-centric antennas. In general, the problem of an antenna placed on or in the human body can be treated as a so-called "boundary value problem" where the human body is considered as a lossy medium. However, in reality and simplicity, an individual case is treated appropriately in a specific manner by numerical simulation such as the FDTD technique. The paper introduces a few examples of wearable antennas as well as implantable antennas developed and tested in our laboratory. In addition, the paper describes some challenges of human-centric antennas.
11:50 Affordable Phased-Arrays for 5G and SATCOM: Ending the Marconi Era
Gabriel Rebeiz (UCSD, USA)
This talk will present the latest work on microwave and mm-wave phased arrays at UCSD and in the world. The talk shows that one can build affordable phased arrays using low-cost silicon-RFICs (RF integrated circuits), and these phased-arrays are now being considered to replace the movable reflector for satellite communications on airplanes, ships and moving platforms. The silicon-based phased-arrays are also being considered for terrestrial 5G communication systems, to be employed first to replace the "last mile" for internet and video delivery to homes, and then for high-speed links between base-stations and a mobile user. In this context, phased-array systems achieving Gbps at 300 meters and 1000 meters will be presented. It will be shown that low-cost phased-arrays have changed the way we think about our future communication systems from SATCOM to 5G.

### Monday, March 20, 14:00 - 18:30

#### Sp_P01 Tropospheric Propagation for Space Applications I

Space / Regular Session / Propagation
Room: Oral Sessions: Auditorium Bordeaux
Chairs: Joel Lemorton (ONERA, France), Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium)
14:00 Alphasat Propagation Experiment in Madrid: Results on Excess and Total Attenuation
Jose M Riera and Domingo Pimienta-del-Valle (Universidad Politécnica de Madrid, Spain); Pedro Garcia-del-Pino (Universidad Politecnica de Madrid, Spain); Gustavo Siles (Universidad Privada Boliviana & Universidad Privada Boliviana, Bolivia); Ana Benarroch (Universidad Politécnica de Madrid, Spain)
Universidad Politécnica de Madrid (UPM) is participating in the Alphasat propagation experiment by measuring the copolar level of the Q-Band beacon at 39.4 GHz since April 2014. In this paper the results of the first two complete years of measurements (until March 2016) are presented with regards to excess and total attenuation. The reference level is calculated on an event-by-event basis in the first case, and obtained from GNSS-based gas attenuation in the second one. The results reflect the variability of the meteorological conditions in the climate of Madrid, with strong differences among the months of the year and between the two years, reinforcing the need of having long-term propagation experiments to capture all the variability of the propagation effects.
14:20 Alphasat Q/V-Band Propagation: a Heuristic Approach for Rainy Events Detection
Ada Vittoria Bosisio (CNR-IEIIT c/o Politecnico di Milano, Italy); Roberto Nebuloni (Ieiit - Cnr, Italy); Carlo Riva and Angelo Sileo (Politecnico di Milano, Italy)
A heuristic algorithm based on two threshold values of a scalar indicator, given by the ratio of the brightness temperatures measured by a ground-based radiometer at 31.4 and 23.8 GHz, is employed to detect the presence, if any, of rain events along the Earth to satellite propagation path in the framework of the Alphasat Aldo Paraboni Propagation Experiment. The promising preliminary results have single out the need of a finer identification of the initial and final time of the event toward the prediction of the rain contribution to the total tropospheric attenuation.
14:40 Spectral Coexistence of GEO and MEO Satellite Communication Networks: Differential Total Atmospheric Attenuation Statistics
Charilaos Kourogiorgas and Athanasios D. Panagopoulos (National Technical University of Athens, Greece)
In this paper, the differential total atmospheric attenuation and differential total losses are investigated in the case of spectral co-existence of GEO and MEO constellation satellite communication systems. In order to use larger bandwidth in the next generation satellite communication systems, many radio systems may share the same spectrum. Due to the high interest on MEO constellation systems to increase the data rates, the coexistence between MEO/GEO satellite communication systems could lead to higher bandwidth for both systems. Therefore, the intersystem interference between MEO and GEO communication systems should be investigated for the reliable design of both satellite networks. Therefore it is necessary to develop an accurate channel model for generating total atmospheric attenuation time series. The synthesizer is based on SDESs and incorporates the spatial correlation of all the atmospheric attenuation factors. From the results, it is found that high intersystem interference is induced due to propagation phenomena.
15:00 Clear-Air Scintillation Analysis of Q-Band Alphasat Link at Spino d'Adda Using Radiosounding Data
Augusto Marziani (Sapienza University of Rome, Italy); Fernando Consalvi (FUB, Italy); Carlo Riva (Politecnico di Milano, Italy); Elio Restuccia (Istituto Superiore delle Comunicazione e delle Tecnologie dell'Informazione - MISE, Italy); Frank S. Marzano (Sapienza University of Rome, Italy)
Scintillations affect the propagated signal with an unwanted aleatory oscillation at the receiver. A first analysis of data acquired from Alphasat Q-band receiver station, located in Spino d'Adda (Italy), is performed. Correlation between meteorological measurements at the ground and measured scintillation from the Q-band beacon receiver (i.e., fluctuation of the received electromagnetic field) is investigated. Radiosounding data from north Italy station of "Milano Linate" have been collected for the entire year 2015 and used to calculate the refractive index structure constant. Subsequently the amplitude scintillation variance is derived through the use of the Rytov model on the slant path. Results obtained using the scintillation model are compared with measured data from Alphasat beacon receiver, investigating the statistical correlation in clear air condition between simulated and measured data.
15:20 Evaluation of Recent Prediction Models Using a Long-Term Database of Rainfall Rate Data
Pedro Garcia-del-Pino (Universidad Politecnica de Madrid, Spain); Domingo Pimienta-del-Valle, Ana Benarroch and Jose M Riera (Universidad Politécnica de Madrid, Spain)
The performance of both a recent rainfall rate model and the inter-annual variability prediction method proposed by the International Telecommunication Union has been assessed taking advantage of the availability of 16 years of rain gauge data. The above rainfall rate model produces as well monthly rainfall rate distributions that have been compared with the experimental monthly distributions achieving good results. The procedure proposed in the ITU variability prediction method has been adapted to test its usefulness to estimate monthly and seasonal variability. In some cases, fair agreement has been found between estimated and experimental variability.
15:40 Tropospheric Scintillation Spectra and Transversal Wind Speed for Satellite Links at Very Low Elevation Angles
Martin Rytir (Norwegian Defence Research Establishment (FFI), Norway); Carlo Riva (Politecnico di Milano, Italy); Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium); Terje Tjelta (UiO, Norway)
Simultaneous measurements of tropospheric scintillation on three different satellite beacons at Ka-band are analyzed. The links have elevation angles of 3.3, 21.2 and 22 degrees. Corner frequency of scintillation is used to calculate the transverse wind speed on each of the links and this is compared with the predictions from a numerical weather model. Results for the two links with higher elevation angle show good agreement with each other as well as with the model data. For the link with elevation angle of 3.3 degrees good match with model data is achieved only when theory applicable for outer scale of turbulence smaller than the Fresnel zone is used. Significant changes in scintillation corner frequency during rain events are also observed for the 3.3 degree link. The results indicate that scintillation at very low elevation angles can be composed of different phenomena, leading among others, to different frequency dependence.
16:00 Coffee Break
16:30 Considerations of Rain Cell Size and Statistics for Attenuation Prediction Models
George Brost (Air Force Research Laboratory, USA); Kevin Magde (AFRL, USA)
Physical-based rain attenuation prediction models conventionally assume a deterministic dependence of rain cell size on rainfall rate and uniaxial structure. This study examined the impact of these assumptions on attenuation predictions. In comparison with model predictions that apply an exponential distribution of cell sizes, the deterministic models exhibited a small cell size effect in which the attenuation exceedance probability was clamped due to the limited path through the rain cell. This resulted in an under- estimation of attenuation in many cases. A biaxial rain-cell attenuation prediction capability was developed to model observed biaxial rain cell shapes and orientational distributions.
16:50 Depolarization Effects on Satellite Links Evaluated Using Five-year Experimental Drop Size Distributions
Jose Garcia-Rubia (Virginia International University, USA); Jose M Riera and Ana Benarroch (Universidad Politécnica de Madrid, Spain); Pedro Garcia-del-Pino (Universidad Politecnica de Madrid, Spain)
Drop Size Distributions (DSDs) measured with an optical disdrometer in Madrid during 5 years are used to derive the copolar attenuation (CPA) and cross polarization discrimination (XPD) at 19.7 and 39.4 GHz. A full wave Method of Moments (MoM) is utilized to calculate specific attenuation and phase rotation through a realistic scattering raindrop model for large raindrops. The best-fit parameters are compared with those given in the ITU-R Recommendation P.618-12. Significant differences are observed for vertical and horizontal polarizations at 19.7 and 39.4 GHz. In this paper, yearly variability of XPD and fitting parameters are presented.
17:10 Preliminary Analysis of Atmospheric Attenuation and Sky Brightness Temperature at Deep-Space Antenna Site of Cebreros for Communications in Ka Band
Andrea Giannini and Mattia Mercolino (European Space Agency, Germany); Alberto Graziani (Université Catholique de Louvain, Belgium); Antonio Martellucci (European Space Agency, The Netherlands)
The move towards higher frequency bands like 26GHz or 32GHz for scientific satellite data downlinks calls for the need to better characterise the atmosphere at the sites where ground antennas are located. For this reason ESA is undertaking the deployment of microwave radiometers at its Deep Space station locations. This paper reports the results of the first two years of site characterisation at the ESA Deep Space antenna 2 located in Cebreros, Spain.
17:30 Performance of Equatorial Multiple-Site Diversity Systems Evaluated from Rain Rate Time Series
Michele D'Amico and Andrea Manzoni (Politecnico di Milano, Italy); Boris Ramos (Escuela Superior Politécnica del Litoral (ESPOL), Ecuador); José Luis Santos (Escuela Superior Politécnica del Litoral, Ecuador)
For the last decades satellite communication systems have been moving towards higher and higher frequencies; rain attenuation along the Earth-satellite path can be an important limiting factor for the system availability, especially in tropical regions where rain events can be particularly intense. One of the possible countermeasures is site diversity. In this paper we evaluate the performance of small-scale, multiple-site diversity systems, through simulations performed on rain-rate time series gathered by four rain gauges located in the equatorial city of Guayaquil, Ecuador. The results show a considerable improvement in terms of performance of the system.
17:50 Optical Satellite Links Channel Modeling: Time Series Generator and Mitigation Techniques Evaluation
Nikolaos Lyras, Charilaos Kourogiorgas and Athanasios D. Panagopoulos (National Technical University of Athens, Greece)
The employment of optical frequencies in satellite communication systems has been proposed in order to cover the huge needs for capacity in the next decade. The reliable design and the prediction of the performance of optical satellite links need accurate channel modeling in the form of time series generators. Considering cloud free line- of-sight (CFLOS) satellite links, turbulence effects on the received signal contain the dominant fading mechanism. In this paper a methodology for generating time series of irradiance due to turbulence for optical satellite uplink scenario is presented. The time series generator takes advantage of the use of Stochastic Differential Equations SDEs driven by Brownian motion. The methodology is applied for several hypothetical links in Greece for the generation of first order statistics of received power. Moreover small scale and large scale diversity techniques are evaluated for the mitigation of turbulence effects.
18:10 An Advanced Propagation Tool for Satellite ATM and Aeronautical Communications
Joel Lemorton (ONERA, France); Jonathan Israel (ONERA - The French Aerospace Lab, France); Thomas Jost and Michael Walter (German Aerospace Center (DLR), Germany); Alberto Graziani (Université Catholique de Louvain, Belgium); Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium); Nicolas Floury (ESA, The Netherlands)
The objective of this paper is to present the development of a new software tool for the analysis of propagation effects on satellite-to-aircraft communications, valid for frequencies between VHF and Ka-band, and which takes into account the following technical/scientific issues: • modifications induced on the aircraft antenna pattern by its installation on the platform (due to interaction with the structural elements of the platform) and corresponding short delay additional multipaths, including in the case of moving elements (e.g. helicopter blades), • geometry of the trajectory and aircraft dynamics during movements including attitude, • surface scattering effects for sea and ground surfaces, including vegetation layers, • atmospheric effects due to troposphere at different altitudes and ionosphere.

#### CS31 New Trends in Reflectarrays and Transmitarrays

Space / Convened Session / Antennas
Room: Oral Sessions: Auditorium Havane
Chairs: Angelo Freni (University of Florence, Italy), Paola Pirinoli (Politecnico di Torino, Italy)
14:00 Dual-Band Dual-Polarized Transmitarrays At Ka-band
Trung Kien Pham (University of Rennes 1 & IETR, France); Ronan Sauleau (University of Rennes 1, France); Erwan Fourn (INSA of Rennes & IETR, France); Fatimata Diaby (Université Grenoble-Alpes & CEA, France); Antonio Clemente (CEA-LETI Minatec, France); Laurent Dussopt (CEA, LETI, Minatec, France)
Transmitarray antennas with dual-band and dual-polarization capabilities are studied here numerically. The antennas are designed based on linearly-polarized unit-cells working at Ka-band for satellite applications. The unit-cells include two printed patches and a connecting via; a 180° phase shift is obtained by rotating one of the patches. The dual-band property is achieved by interleaving unit-cells dedicated to each band, and two different polarizations in each band. The numerical results demonstrate the working principles of dual-band dual-polarized transmitarrays.
14:20 Investigation on Double Layer Conformal Reflectarray Antenna
Michele Beccaria, Paola Pirinoli and Mario Orefice (Politecnico di Torino, Italy)
In this communication the possibility of enhancing the radiation performances of a printed Convex Conformal Reflectarray is investigated. In particular, results on the effect of the use of dual layer stacked patches as re-radiating elements are shown.
14:40 A Dual-CP Reflectarray Unit Cell for Realizing Independently Controlled Beams for Space Applications
Mehdi Hosseini and Sean V Hum (University of Toronto, Canada)
The paper presents a dual circular polarization unit cell for realizing a reflectarray that synthesizes two independent patterns based on the polarization of the incident field. To this end, a thin polarizer, which converts incident circularly polarized (CP) waves into orthogonal linearly polarized (LP) waves, is cascaded with a dual-linear-polarization (DLP) reflectarray. The reflectarray then applies the required reflection phases to the LP waves. The proposed antenna system is structured by placing the polarizer adjacent to the DLP reflectarray. Numerical simulations are arranged to assess the performance and ability of a 20 GHz unit cell design in providing high polarization purity and independent reflection phases for orthogonal CP waves. Enclosing 4×4 polarizer cells as small as 0.14λ×0.14λ, the unit cell features an overall thickness of ~1λ and lateral dimensions of 0.55λ×0.55λ.
15:00 High-Performance Curved Contoured Beam Reflectarrays with Reusable Surface for Multiple Coverages
Min Zhou and Stig Sørensen (TICRA, Denmark); Rolf Jørgensen (Ticra, Denmark); Oscar Borries and Erik Jørgensen (TICRA, Denmark); Giovanni Toso (European Space Agency, The Netherlands)
An investigation of curved contoured beam reflectarrays with reusable surface for multiple coverages is presented. The main advantage of curved reflectarrays over shaped reflectors is that they allow the possibility of reusing a standard parabolic mold for multiple missions. To demonstrate this, two curved reflectarrays are designed using the direct optimization technique to fulfill the requirements of two contoured beam missions in both transmit and receive frequency bands for dual linear polarization. The two reflectarrays use the same curved surface, f/D, dimension, and feed, and by changing the reflectarray element pattern, two completely different coverages can be produced while maintaining a performance that is comparable to that of the shaped reflector.
15:20 Dual Reflectarray Antennas for Contoured Beam and Beam Scanning Applications
Carolina Tienda (Airbus Defence and Space, United Kingdom (Great Britain)); Jose A. Encinar and Mariano Barba (Universidad Politecnica de Madrid, Spain); Manuel Arrebola (Universidad de Oviedo, Spain)
Two dual reflectarray antennas able to provide an European coverage and beam scanning over 8º respectively have been presented. An accurate technique has been proposed for the analysis of dual-reflectarray antennas, which takes into account the angle of incidence of the field impinging on main reflectarray cells. Two 50-cm antenna demonstrators with the same geometry have been manufactured and measured in a compact range. The measured radiation patterns for the contoured beam antenna are in good concordance with the simulations and practically fulfill the coverage requirements with a cross-polar discrimination better than 25 dB in the frequency band 12.975 GHZ- 14.25 GHz. The measured radiation patterns of the beam scanning antenna are in good agreement with the simulations for transmit and receive frequency bands in Ku-band with a cross-polar discrimination better than 30 dB within a scanning range of +4°.
15:40 Dual-Polarization Reflectarray in Ku-band Based on Two Layers of Dipole-Arrays for a Transmit-Receive Satellite Antenna with South American Coverage
Jose A. Encinar (Universidad Politecnica de Madrid, Spain); Rafael Florencio (Universidad de Sevilla, Spain); Manuel Arrebola (Universidad de Oviedo, Spain); Miguel Salas (Technical University of Madrid, Spain); Mariano Barba (Universidad Politecnica de Madrid, Spain); Rafael R. Boix (University of Seville, Spain); Giovanni Toso (European Space Agency, The Netherlands)
A 1.1-m reflectarray antenna has been designed, manufactured and tested to fulfil the requirements of a satellite antenna in Ku-band to provide a South American coverage in Tx and Rx. The reflectarray cells consist of four dipoles for each polarization in two dielectric layers, which were selected because of their simplicity and high performance. The dipole dimensions are optimized in all the reflectarray cells to accomplish the prescribed radiation patterns, by iteratively calling an analysis routine based on MoM-SD and local periodicity. The measured radiation patterns of the manufactured antenna have been satisfactorily compared with simulations and with a 3-layer reflectarray previously designed for the same mission.
16:00 Coffee Break
16:30 Advanced Learning-Based Approaches for Reflectarrays Design
Lorenza Tenuti (ELEDIA Research Center, University of Trento, Italy); Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy); Daniele Bresciani (Thales Alenia Space, France); Andrea Massa (University of Trento, Italy)
The problem of efficiently and effectively compute the response (i.e., reflection coefficients) of next-generation reflectarray elements with wide number of degrees-of-freedom is addressed in this work. Towards this end, a machine learning- based approach based on advanced Kriging strategies is exploited (instead of classical full-wave solvers) in order to predict the response of complex unit cells of interest for the design of high-performance reflectarrays. Preliminary numerical results aimed at comparing the accuracy and efficiency of the proposed methodology with respect to standard full-wave approaches are illustrated.
16:50 Exploiting Non-Radiating Currents in Reflectarray Antenna Design
Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy); Angelo Gelmini (ELEDIA Research Center, University of Trento, Italy); Marco Salucci (ELEDIA Research Center, Italy); Daniele Bresciani (Thales Alenia Space, France); Andrea Massa (University of Trento, Italy)
A new paradigm for the design of reflectarrays is introduced. The proposed methodology allows the designer to specify constraints/simplifications on the antenna surface current distribution thanks to an innovative exploitation the non-radiating (NR) component, which is regarded a powerful additional degree-of-freedom (DoF) in the synthesis process. An illustrative example is presented, aimed at nulling the current density within a selected sub-region of a planar reflectarray by means of a suitable particle swarm optimization (PSO) of the NR contribution. The effectiveness and the potentialities of the proposed feasible source synthesis methodology are verified by means of a numerical benchmark, opening the doors to a completely new horizon in the design of next generation reflectarrays.
17:10 Demonstration of a High-Efficiency Reflectarray Antenna at 1 THz Based on Dielectric Resonators
Eduardo Carrasco (Foundation for Research on Information Technologies in Society, IT'IS, Switzerland); Daniel Headland (The University of Adelaide, Australia); Shruti Nirantar (RMIT University, Australia); Withawat Withayachumnankul (The University of Adelaide, Australia); Philipp Gutruf (Northwestern University & Rogers Research Group, USA); James Schwarz (RMIT University, Australia); Derek Abbott (The University of Adelaide, Australia); Madhu Bhaskaran and Sharath Sriram (RMIT University, Australia); Christophe Fumeaux (The University of Adelaide & School of Electrical and Electronic Engineering, Australia)
A reflectarray antenna composed of more than 87000 single-crystal silicon resonators on a gold ground plane is experimentally demonstrated to achieve efficient beam focusing at 1 THz. The functionality of the reflectarray as a collimator is also verified by the principle of antenna reciprocity. Because of the low-loss and nondispersive nature of high-resistivity silicon in the submillimeter regime, the losses of the reflectarray are negligible, a very desirable feature at such frequencies. Reflectarrays based on dielectric resonator antennas (DRA) have been relatively unexplored in the terahertz range, mainly because of the challenging fabrication process.
17:30 Single-Layer Reflectarrays - Past, Present and Future
Y. Jay Guo and Peiyuan Qin (University of Technology, Sydney, Australia)
This paper presents an overview of the advances in single layer reflectarrays. In particular, it reports the progress in wideband reflectarrays and reconfigurable reflectarrays.
17:50 Estimation of Frequency Characteristics of Reflectarray by Introducing Aberration Theory
Shigeru Makino, Kento Takeshima, Tetsuo Hirota, Keisuke Noguchi and Kenji Itoh (Kanazawa Institute of Technology, Japan); Takeshi Shiode and Michio Takikawa (Mitsubishi Electric Corporation, Japan)
In this paper, aberration theory will be introduced to estimate the frequency characteristics of reflectarrays. By introducing aberration theory, the mechanisms of the frequency characteristics of the beam squint and the phase errors on the aperture will be qualitatively clarified. The validity will be quantitatively verified by simulations.
18:10 Improving Convergence in Crosspolar Optimization of Reflectarray Antennas
Daniel R. Prado (Universidad de Oviedo & Group of Signal Theory and Communications, Spain); Manuel Arrebola, Marcos R. Pino and Fernando Las-Heras (Universidad de Oviedo, Spain)
Two techniques are compared for the crosspolar optimization of reflectarray antennas using a full-wave analysis technique based on local periodicity directly in the optimization process within acceptable computing time. The first one is based on the Levenberg-Marquardt Algorithm (LMA) while the second technique is based on the generalized Intersection Approach framework using the LMA as backward projector. As full-wave analysis technique, a spectral domain Method of Moments based on local periodicity is employed. Two test cases are provided to show the capabilities and limitations of the techniques. The optimization is carried out in different computers to assess their scalability properties. In addition, the convergence of both techniques is compared in terms of number of iterations and results achieved.

### Monday, March 20, 14:00 - 16:00

#### CS19 High-Data Rate Wireless Connectivity for Smart Rail Mobility

Wireless Networks / Convened Session / Propagation
Oral Sessions: Room 341
Chairs: Cesar Briso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain), Juan Moreno (Metro de Madrid S.A. & Universidad Politécnica de Madrid, Spain)
14:00 How to Provide Ultrabroadband Services in Train to Ground Communications Today
Ron Porter and Nir Hayzler (RADWIN, Israel); Carlos Martinez (RADWIN, Spain)
The Transportation environment is a varied vertical that refers to various metro & train scenarios (both under and above ground). A wireless connectivity system is used to provide high-throughput and reliable wireless connectivity between moving trains and static base-stations installed along the tracks in all scenarios. The system should be designed to meet the following set of unique requirements for the transportation segment:High throughput and stable performance (low latency and jitter) to support variety of services as high definition (HD video), VoIP Telephony and high capacity Internet access In this paper RADWIN explains some topics on how to achieve the above.
14:20 Wireless Channel Measurements and Modeling for TCMS Communications in Metro Environments
Iñaki Val, Aitor Arriola and Pedro Rodriguez (IK4-IKERLAN, Spain); Ana Gonzalez-Plaza and David Alonso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain); Lei Zhang (Universidad Politecnica de Madrid, Spain); Cesar Briso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain); Juan Moreno (Metro de Madrid S.A. & Universidad Politécnica de Madrid, Spain); Carlos Rodríguez Sánchez (Metro de Madrid S.A., Spain); Eneko Echeverria and Javier Goikoetxea (Construcciones y Auxiliar de Ferrocarriles, S. A. (CAF), Spain)
In this paper, channel measurements for the 2.6 GHz band in railway environments are presented. The measurements have been carried out in the subway of Madrid in different environments (tunnel, station and open air scenarios). An intra-consist link for a future wireless Train Control and Management System (TCMS) has been measured for two types of trains, a continuous train and a non-continuous train. The results in these two trains allow checking the impact of the separation between cars in this type of links and the influence of the environment. Wideband and narrowband measurements have been carried out, and Power Delay Profile (PDP), delay spread and pathloss have been extracted and are shown in this paper. Results are useful for the design of communications systems inside train cars.
14:40 Scenario Modules and Ray-Tracing Simulations of Millimeter Wave and Terahertz Channels for Smart Rail Mobility
Ke Guan (Beijing Jiaotong University, P.R. China & Technische Universität Braunschweig, Germany); Xue Lin and Danping He (Beijing Jiaotong University, P.R. China); Bo Ai (Beijing Jiaotong University & State Key Lab of Rail Traffic Control and Safety, P.R. China); Zhangdui Zhong (Beijing Jiaotong University, P.R. China); ZhuYan Zhao, Deshan Miao and Hao Guan (Nokia Siemens Networks, P.R. China); Thomas Kürner (Technische Universität Braunschweig, Germany)
Nowadays, rail traffic is expected to evolve into a new era of smart rail mobility", which requires a seamless high-data rate wireless connectivity with up to dozens of GHz bandwidth. Such a huge bandwidth requirement motivates the exploration of the underutilized millimeter (mm) wave and Terahertz (THz) bands. In this paper, six scenario modules for mm wave and THz train-to-infrastructure channels are defined and constructed for the first time. All the main objects, such as tracks, stations, crossing bridges, tunnels, cuttings, barriers, pylons, buildings, vegetation, traffic signs, billboards, trains, etc., are modeled according to the typical geometries and materials in reality. Ray-tracing simulations show that these objects indeed influence mm wave channel properties, and therefore, they can even play a more important role in the channels at higher frequency bands -- THz. The modules presented in this paper are constructed through abstracting commonness of typical rail traffic scenarios.
15:00 Wireless Broadband Train to Ground Network Performance in Metro Deployments
Julian Andrade, Carlos Moreno and Joan Vila (Huawei Technologies, Spain)
This paper presents the performance testing of a train to ground communications network deployed in an underground environment and based on IEEE 802.11ac wireless technology. A fully operational pilot project was deployed in Metro de Madrid facilities for studying the feasibility and performance of the solution. Wireless nodes have been installed in the tunnel and onboard the train. During the testing the train was moving between two stations while measuring the signal level received by the train wireless node and the TCP data throughput achieved between train and ground nodes.
15:20 WLAN Propagation Measurements in Railway Tunnels. Case Study: Madrid Metro
Ignacio Bravo-Llano (Belden, Spain); Carmen Arteaga-González and Daniel Sánchez de Marcos (Alstom Transport Information Solutions, Spain)
In this work, we do an empirical approach to identify 802.11n technology Train to Ground communication specifics in underground applications from an industrial point of view. The equipment for the measurements was located aboard and along a track. The experiments consisted on measuring signal to noise ratio levels and beacon loss along a standard train cycle for physical layer performance assessment. Due to fading effects found, a break-even point should be found for Signal to Noise Ratio (SNR) Averaging level, crucial for fast handover in Dynamic Frequency Selection (DFS) environments.
15:40 Propagation Measurements with Regional Train at 60 GHz for Virtual Coupling Application
Kun Yang (Super Radio AS, Norway); Marion Berbineau (IFSTTAR, COSYS & University Lille Nord de France, France); Jean-Pierre Ghys (IFSTTAR, COSYS, LEOST, University Lille Nord de France, France); Yann Cocheril (IFSTTAR, France); Divitha Seetharamdoo (IFSTTAR, LEOST & Univ Lille Nord de France, France)
A millimeter-wave (mmW) radio channel measurement campaign at 64.5 GHz for train's virtual coupling application was performed in a regional train in France. In this paper, we give a brief description of the channel sounder design and channel measurement campaigns with four dedicated scenarios including different setups and other channel parameters. The results of angular power distribution obtained by sweeping a horn antenna at the receiver side shows that the difference of the received signal levels (RSL) obtained at different azimuth angle of the same location can vary from 5 dB to 12 dB depending on different scenarios.

#### C_P01 Millimeter Wave Radio Channels I

Cellular Communications / Regular Session / Propagation
Oral Sessions: Room 342A
Chairs: Sana Salous (Durham University, United Kingdom (Great Britain)), Reiner S. Thomä (Ilmenau University of Technology, Germany)
14:00 Validation of Emulated Omnidirectional Antenna Output Using Directive Antenna Data
In this paper, we present validation of a method for constructing a virtual omnidirectional antenna in the azimuth plane. The virtual omnidirectional antenna utilizes a combination of data from directive horn antennas. The aim is to utilize the high gain of the horn antenna to improve the dynamic range of channel sounding measurements conducted in the centimeter and millimeter wave bands. The resulting complex impulse response from the virtual omnidirectional antenna is used to find the power-delay-profile (PDP). This is then compared to measurements conducted at the same time using a real omnidirectional antenna. The validation shows that the synthesized omnidirectional is capable of predicting main components and the slope of the PDP. Further, it is shown that by choosing angular sampling steps corresponding to the half power beam width (HPBW) of the used antenna similar power levels can be achieved.
14:20 Mixing Deterministic and Stochastic Propagation for Assessing MmWave Small-cell Networks
Romain Charbonnier, Mohammed Zahid Aslam and Yoann Corre (SIRADEL, France); Yves Lostanlen (SIRADEL & University of Toronto, Canada)
Ray-based and hybrid propagation models are today considered as valuable solutions to fulfill 5G wireless channel modeling requirements. They are a complement or alternative to the stochastic approaches when link-level and system-level simulations deal with millimeter-wave (mmWave), ultra-dense deployment and/or large antenna arrays. The present article proposes an extension of an urban ray-based model for the assessment of a 60-GHz outdoor small-cell network. The multi-paths are predicted from interactions with the static environment, but also with randomly-positioned vehicles and user-bodies. Both the vehicles and the user-body generate ray-path blockage, and (in case of the vehicle) new propagation paths. This sometimes affects the cell selection or beam orientation, and significantly changes the received signal strength and inter-cell interference. The user-body blockage is illustrated on two simple use cases (single-cell and two-cell scenarios). Then the impact of both stochastic components is assessed through the performance simulation of a whole mmWave small-cell network.
14:40 Frequency and Bandwidth Dependence of Millimeter Wave Ultra-Wide-Band Channels
Naveed Iqbal (Huawei Technologies, Germany); Jian Luo (Huawei Technologies Duesseldorf GmbH, Germany); Christian Schneider and Diego Dupleich (Ilmenau University of Technology, Germany); Stephan Haefner (Technische Universität Ilmenau, Germany); Robert Müller (TU Ilmenau, Germany); Reiner S. Thomä (Ilmenau University of Technology, Germany)
If a channel is frequency dependent then Uncorrelated Scattering (US) (a narrow-band assumption) don't hold. This has a significant impact at the considered channel modeling methodology as delay and angular dispersion of waves can no longer be studied independently because the small scale fading of individual multipath components become correlated. In this paper, we investigate the frequency dependence of the 30 GHz millimeter-Wave (mmWave) Ultra-Wide band (UWB) channel. Our indoor small lecture room measured channel results show that both delay and angular spreads vary significantly for different frequencies within a measured UWB channel. This is due to different interactions with objects in the environment due to significant difference in the comparative wavelengths. Therefore, we stress that mmWave-UWB channel modeling methodology must take into account the frequency dependence of channel parameters. In order to support its significance, we have also provided an evidence from mmWave system architecture point of view.
15:00 Analytic and Experimental Investigation of Beamforming Algorithms for MM-Wave Channel Characterization
Fengchun Zhang, Wei Fan and Gert Pedersen (Aalborg University, Denmark)
Beamforming algorithms are expected to be extensively utilized in mm-wave systems to improve system performance. In this paper, we discuss three different beamforming algorithms based on uniform circular arrays (UCAs), i.e. classicial beamfomer, coventional frequency invariant beamformer. Numerical simulation results and channel sounding measurement results at mm-wave are provided to demonstrate and compare the performance of the different beamformers in channel parameter estimation applications.
15:20 Reflector Design to Mitigate Finger Effect on 60 GHz User Devices
Mikko Heino (Aalto University, Finland); Clemens Icheln (Aalto University & School of Electrical Engineering, Finland); Katsuyuki Haneda (Aalto University, Finland)
In this paper, we propose a novel method to mitigate the strong shadowing effect a nearby finger has on the antenna of a handheld communications device operating at 60 GHz, by introducing reflectors on the device. When the finger is located at the distance of 3 mm of the antenna, it causes strong shadowing and the far-field radiation attenuation behind the finger is 25-34 dB. In this paper, we show that a parabolic reflector collar" that is placed around the antenna array can significantly reduce the shadowing in the far-field. With the collar, the far-field radiation behind the finger is improved by 19-25 dB, making the array usable even when covered by a finger. The effect of reflector size and location is studied.
15:40 Miners Shadowing Effects on 60 GHz Transmission Rate in Underground Mine Ricean Channels
Mohamad Ghaddar (University of Quebec (UQAT), Canada); Mourad Nedil (UQAT, Canada); Larbi Talbi (University of Quebec - Outaouais, Canada); Tayeb A. Denidni (INRS-EMT, Canada)
Practically, 60 GHz wireless communications require highly directional antennas to overcome the severe free space loss. In underground mines, the effects of the complete blockage of line-of-sight (LOS) by miners are unavoidable. This paper presents an experimental study for assessing NLOS miner shadowing effects (MSE) on data transmission. Thus, two separate measurement scenarios are performed with and without the presence of a miner in the channel i.e, LOS, and NLOS MSE. Result show that, LOS underground mines are Ricean channels with a K-factor of 9.3 dB. However, the presence of a miner restrains K-factor to 3.6 dB. Furthermore, the experimental channel bit error rate (BER) are validated theoretically. Thus, confirming that under MSE scenario, an additional SNR of more than 13 dB is required to yield a BER of 10-4 as compared to LOS case.

#### B_A01 Antennas for Biomedical Applications

Biomedical / Regular Session / Antennas
Oral Sessions: Room 342B
Chairs: Marco A. Antoniades (University of Cyprus, Cyprus), Stavros Koulouridis (University of Patras, Greece)
14:00 Investigation of Inductive and Radiating Energy Harvesting for an Implanted Biotelemetry Antenna
Quang-Trung Luu (UMR 8507 CNRS, CentraleSupélec, UPMC, Université Paris-Sud, France); Stavros Koulouridis (University of Patras, Greece); Antoine M Diet (Paris Saclay - Université Paris Sud ( GeePs UMR 8507 - IUT de Cachan ), France); Yann Le Bihan (GEEPS, France); Lionel Pichon (CentraleSupélec - CNRS - Université Paris Sud & GeePs Laboratory, France)
A coil is integrated inside an implanted antenna in order to support inductive charging. The implanted antenna has been designed for wireless data telemetry at 402MHz region and radiating wireless charging at 915MHz. The antenna-coil system is embedded into a three layer canonical model of human arm. In the inductive charging case an external transmitting coil is considered while in the radiating charging scenario a dipole is implemented. Several simulations are carried out for the antenna-coil system. While radiating charging seems to be more efficient inductive charging can be used as a complimentary solution since they both can coexist
14:20 Conformal Wearable Monopole Antenna Backed by a Compact EBG Structure for Body Area Networks
Marco A. Antoniades (University of Cyprus, Cyprus); Muhammad Ali Babar Abbasi (Frederick University, Cyprus); Marija Nikolic (University of Belgrade, Serbia); Photos Vryonides (Frederick University Cyprus, Cyprus); Symeon Nikolaou (Frederick Research Center, Cyprus)
A compact planar monopole antenna backed by an electromagnetic bandgap (EBG) structure is presented. The antenna is conformal to the human body and is intended for wearable applications in wireless body area networks. It operates at 2.45 GHz, and is fabricated on a 68mm by 38mm by 1.57mm semi-flexible substrate. The performance of the antenna does not degrade with structural bends along both of its axes, thus making it robust to structural deformation. In all cases it maintains a fractional impedance bandwidth in the range of 5%, with a gain ranging from 6.3 to 6.7 dBi. The antenna performance is also insensitive to the antenna location on the human body. For placements of the antenna on the arm, chest and leg, it maintained a 5% impedance bandwidth with radiation efficiencies above 70% and an average gain of 7.3 dBi.
14:40 UWB On-body Slotted Patch Antennas for In-Body Communications
Enrique Miralles and Carlos Andreu (Institute of Telecommunications and Multimedia Applications, Spain); Marta Cabedo-Fabrés (Universidad Politécnica de Valencia, Spain); Miguel Ferrando-Bataller and Jose F Monserrat (Universitat Politècnica de València, Spain)
One of the most relevant challenges of next generation in-body devices consists in enhancing the medical applications of wireless networks qualitatively. The current standard does not allow high data rate wireless connections between implanted nodes. UWB systems have been considered as a potential candidate for future in-body devices. To establish a proper link within UWB, antenna matching should be ensured within the frequency range of interest. Besides, a good wave penetration trough the biological tissues is totally essential. In this work, several UWB on-body slotted patch antenna models are assessed and discussed. According to the propagation medium, the on-body antenna designs have been miniaturized and optimized taking into account the dielectric properties of human tissues. After a thorough comparison between antenna models, an optimized model has been manufactured. Finally, the performance of the optimized antenna prototype has been assessed.
15:00 Flexible Antenna Array for Wearable Head Imaging System
Mohd Saiful Riza Bashri (The University of Edinburgh, United Kingdom (Great Britain)); Tughrul Arslan (University of Edinburgh & Sensewhere Ltd., United Kingdom (Great Britain)); Wei Zhou (Sofant Technologies, United Kingdom (Great Britain))
In this paper, a flexible directional monopole antenna for wearable head imaging system for stroke detection is presented. To ensure better flexibility for wearable applications, a very thin flexible PET substrate, Melinex 339 with thickness of 75µm is utilized. The size of the antenna is 70mm × 30mm. An array of 8 antennae are arranged in elliptical configuration to follow a human head contour. The antennae operate at frequency of 1.3GHz to 3.5GHz which would provide sufficient penetration and resolution. These antennae were designed and optimized to work in close proximity with human head. An investigation on mutual coupling between neighboring antennae when in close proximity with artificial human head and on free space is carried out via CST Microwave Studio and experimentation. Specific Absorption Rate (SAR) with different transmitted power level are simulated to ensure that the electromagnetic wave absorbed by human head is below the safety limit.
15:20 Performance of Embroidered Higher-Order Mode Antennas with Different Stitching Patterns
Roy B. V. B. Simorangkir (Macquarie University, Australia); Yang Yang (University of Technology Sydney, Australia); Karu Esselle (Macquarie University, Australia)
In this paper the performance of TM21 resonance-mode circular patch antennas embroidered with different stitching patterns is discussed and compared. The goal is to investigate the difference in the performance when the antenna is embroidered with stitches following the antenna current paths as opposed to some simple patterns such as horizontal and vertical ones. This creates an alternative solution for embroidering prototypes of wearable antennas with complicated current distributions. The results reveal that by embroidering the antenna in line with the complex TM21 current distribution a good monopole-like radiation pattern is achieved, which is close to an etched copper prototype's used as the reference. However, with a dense horizontal stitching pattern an acceptable monopole-like radiation pattern can also be achieved with quite good gain and efficiency. While simplifying the embroidery process, the use of the simple horizontal pattern with high density suffers from high cross-polarization and thread consumption as compromises.
15:40 A Digitally Assisted Repeater Antenna for Implant Communications
Sema Dumanli (Toshiba Research Europe Ltd., United Kingdom (Great Britain))
The wireless link between an implant and an off-body gateway may be difficult to secure due to the fact that electromagnetic waves quickly attenuate through human tissues. The signal strength may be quite weak by the time the waves reach the skin. In order to address this problem, a digitally assisted repeater antenna has been designed to be located outside of the patient's body, and act as a relay between the implant and the off-body gateway. The radiation pattern is switched between two modes depending on the link formed: in-body or off-body link. With an overall size of 30x30x3.15mm, the antenna operates in the 2.4GHz ISM band. The repeater is aimed to be used to secure wireless communications with a hip implant. Therefore, for a typical depth of such an implant of 4cm, the repeater has been shown to enable a decrease of 40dB in the transmit power level.

#### H_A02 Mm-Wave Antennas for High Data Rate I

High Data-rate Transfer / Regular Session / Antennas
Oral Sessions: Room 343
Chairs: George Shaker (University of Waterloo & Spark Tech Labs, Canada), Ezzeldin Soliman (The American University in Cairo, Egypt)
14:00 Parallel Fed 2x1 Antenna Array Utilizing Surface Wave Cancellation on LTCC Substrate
Josef Hagn (Intel Deutschland GmbH, Germany); Valerio Frascolla (Intel Deutschland Gmbh, Germany); Ronan Sauleau (University of Rennes 1, France); Jouko Aurinsalo (VTT Technical Research Centre of Finland, Finland); Markku Lahti (VTT Electronics, Finland); Kari Kautio (VTT Technical Research Centre of Finland Ltd, Finland)
In this paper a novel design of an UE (User Equipment) antenna for the 60-GHz band is presented. The antenna was realized on LTCC A6M-E substrate to ease a later integration with the RF-chipset on a single module. To satisfy the requirement of a relative bandwidth of 15% an electrically thick substrate was utilized, which unfortunately leads to an undesired excitation of surface waves. A suppression of these dielectric modes was achieved by employing a cancellation technique of excited surface waves. The proposed antenna consists of two parallel fed aperture coupled microstrip patch antennas. The S-parameter and radiation pattern results (simulation and measurement) are presented and are used to verify the antenna design. The manufactured antenna exhibits a -10dB impedance bandwidth of more than 9GHz, a Half Power Beam Width (HPBW) greater than 60° and a realized gain of more than 5.5dBi over the bandwidth.
14:20 Stacked Patch Antenna Sub-array with Low Mutual Coupling for 79 GHz MIMO Radar Applications
Mohammad Mosalanejad (KU Leuven & IMEC, Belgium); Steven Brebels (IMEC, Belgium); Ilja Ocket (IMEC & ESAT-TELEMIC, KU Leuven, Belgium); Charlotte Soens (Imec, Belgium); Guy A. E. Vandenbosch (Katholieke Universiteit Leuven, Belgium)
In this paper, new wideband cavity backed aperture coupled microstrip antenna is presented for 79 GHz MIMO radar applications. This designs is based on a sub-arrays consisting of two single elements, which have stacked rectangular patch radiators. A microstrip to stripline transition and a series feeding topology is used to feed the elements. The antennas are manufactured by using a new high resolution multi-layer PCB technology. The performance of this antennas have been verified by both simulations and measurements. Antenna bandwidth is 9.7%, and the gain is more than 5.2dBi. Large beam widths of 138 degrees in E-plane and 40 degrees in H-plane are obtained. Antenna radiation efficiency is more than 75%, the mutual coupling between the array elements is less than -18dB.
14:40 High-Efficiency & Wideband Aperture Coupled Patch Antenna Fed by a Dielectric Waveguide
Nour Nachabe (University of Nice Sophia Antipolis, France); Cyril Luxey (University Nice Sophia-Antipolis, France); Diane Titz (University Nice Sophia Antipolis, France); Frédéric Gianesello (STMicroelectronics, France); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal)
A key limitation of high gain planar microstrip antenna arrays relies in the high loss of the feeding network. In this paper, we propose an innovative way to solve this issue by feeding a microstrip patch antenna by an aperture coupled dielectric filled waveguide. Using a low loss dielectric, we managed to achieve a low loss and compact waveguide. The proposed antenna supports both V band (57-66 GHz) and E band (71-86 GHz) applications with a matching better than -10 dB and a broadside gain higher than 8 dBi. Simulated gain is notably higher than classical microstrip antenna gain [1], which is related to the high efficiency (> 90%) of the proposed antenna architecture. This innovative antenna could be used as a unit-cell for the design of a compact and high efficiency large antenna array, targeting backhaul communications at V and E bands.
15:00 W-band Series-Connected Patches Antenna for Multibeam Application Based on SIW Butler Matrix
Fengchao Ren (School of Information Science and Engineering, Southeast University, P.R. China); Wei Hong (Southeast University, P.R. China); Ke Wu (Ecole Polytechnique (University of Montreal) & Center for Radiofrequency Electronics Research of Quebec, Canada)
This letter presents a series-connected patch array antenna aperture-coupled by substrate integrated waveguide (SIW), which produces narrowed E-plane beamwidth for improving antenna gain. With this special patch array, W-band multibeam array capable of offering switchable beams in H-plane is designed by means of SIW Butler matrix. The simulation and experiment results show good impedance matching and port-to-port isolation, as well as specific beams associating with four input ports, well demonstrating the validity of this design. Additionally, the antenna is developed by printed circuit board (PCB) technology, characterizing of planar profile, high-level integration, low cost and small weight
15:20 Novel Micromachined On-Chip 10-Elements Wire-Grid Array Operating at 60 GHz
Mai Sallam (The American University in Cairo & Katholieke Universteit Leuven, Egypt); Mohamed Serry (The American University in Cairo, Egypt); Atif Shamim (King Abdullah University of Science and Technology, Saudi Arabia); Sherif Sedky (AUC, Egypt); Ezzeldin Soliman (The American University in Cairo, Egypt)
This paper presents a new topology for a wire-grid antenna array which operates at 60 GHz. The array consists of ten λg/2 dipole radiators connected via non-radiating connectors. Both radiators and connectors are placed on top of narrow silicon walls. The antenna is fed with a coplanar microstrip lines placed at the other side of the wafer and is connected with its feeding transmission lines using through-silicon-vias. The antenna is optimized for two cases: using high- and low-resistivity silicon substrates. The former has better radiation characteristics while the later is more compatible with the driving electronic circuits. The antenna has high directivity, reasonable bandwidth and high polarization purity.
15:40 Wideband Cavity-Backed Slot Subarray with Gap Waveguide Feed-network for D-band Applications
Abbas Vosoogh, Ashraf Uz Zaman and Vessen Vassilev (Chalmers University of Technology, Sweden)
simple and wideband subarray for D-band applications is presented in this paper. The proposed multilayer subarray consists of 2x2 cavity-backed slot subarray fed by a ridge gap waveguide transmission line. The simulated results show that the proposed subarray has a relative impedance bandwidth of 22.5% with input reflection coefficient better than -10 dB over the 126-158 GHz frequency band. An array antenna consisting of 8x8 slots is designed with the proposed subarray. The simulation results of the proposed subarray and antenna are presented.

### Monday, March 20, 14:00 - 18:30

#### CS20 In Memory of Prof. Per Simon Kildal (Dedicated session)

Future Applications / Convened Session / Antennas
Oral Sessions: Room 351
Chairs: Madeleine Schilliger Kildal (Chalmers University of Technology & Bluetest AB, Sweden), Stefano Maci (University of Siena, Italy), Eva Rajo-Iglesias (University Carlos III of Madrid, Spain), Zvonimir Sipus (University of Zagreb, Croatia)
14:00 Remembering Per-Simon Kildal: Soft in Heart and Hard in Technical Work
Yahya Rahmat-Samii (University of California Los Angeles (UCLA) & UCLA, USA)
Professor Per-Simon Kildal passed away on April 21, 2016, after a very short period of illness. He was born on July 4, 1951. He chaired the Division of Antenna Systems of the Department of Signals and Systems at Chalmers University of Technology. He authored an antenna textbook and many journal articles and conference papers. He designed two very large antennas, including the Gregorian dual-reflector feed of the Arecibo radio telescope. He was the originator of the concept of soft and hard surfaces, recently resulting in the gap waveguide, a new low-loss meta-material-based transmission line. His research group pioneered the reverberation chamber into an accurate measurement tool for antennas and wireless terminals. Prof. Kildal was the recipient of two Best Paper Awards for articles published in the IEEE Antennas and Propagation Transactions, and he was the recipient of the 2011 Distinguished Achievements Award of the IEEE Antennas and Propagation Society.
14:20 Per-Simon Kildal: Friend, Scientist, Educator, Entrepreneur
Stefano Maci (University of Siena, Italy)
Professor Per-Simon Kildal passed away on April 21, 2016, at age 65. Since 1989, he was a Professor with Chalmers University of Technology, Gothenburg, Sweden, where he led the Division of Antenna Systems of the Department of Signals and Systems. The life of Professor Kildal was dedicated to Science, Education and Engineering. This paper summarizes these three aspects of his life, starting form his main scientific achievements concerned with the Arecibo radio telescope, the invention of ultra-broadband "Eleven antenna", the metasurface precursor concept of "soft and hard surfaces", and the recent "gap waveguide". His contributions on high level education inside the European School of Antennas is reviewed, as well as his entrepreneurship activity, centered around the ideas of reverberation chamber for measurements of wireless terminals, and on electronic packaging by EBG materials.
14:40 Trondheim - The Launching Pad for Per-Simon Kildal's Extraordinary Career
Erik Lier (Lockheed Martin Corporation, USA)
Per-Simon's rise to fame started at the Norwegian University of Science and Technology in Trondheim in the late 1970s. In this paper I will reflect on those years and how it may have shaped his career.
15:00 Applications of Soft and Hard Surfaces in the Era of Metamaterials
Eva Rajo-Iglesias (University Carlos III of Madrid, Spain); Malcolm Ng Mou Kehn (National Chiao Tung University, Taiwan)
During the beginning of the 2000s, amidst the boom of metamaterials, EBG structures and AMC surfaces, the authors of the paper had the privilege of working with Professor Kildal on revisiting the concept of soft and hard surfaces, which was already established for a decade at that time. These belong to the category of artificial surfaces with the ability of providing unexpected boundary conditions in a given frequency range. In parallel with metamaterials, we present a summary of some of the applications that were developed, among them hard waveguides or invisible struts. Meeting Per-Simon has changed our lives for better forever.We are now established researchers and we met him at the beginning of our carriers. We have been very close friends and collaborators with him all along these years. We feel now like orphans and our lives will never be the same without his supportive friendship and inspiration.
15:20 A Clear Path in the Design of Electromagnetic Structures
Zvonimir Sipus (University of Zagreb, Croatia)
This paper overviews the research activities of Prof. Per-Simon Kildal's group regarding structuring the design of different electromagnetic components and software subroutines. Through his work Prof. Kildal always had a clear path in the design process of electromagnetic devices and concepts, and this approach will be demonstrated through a couple of examples. The first will focus on the design of different types of periodic structures through efficient use of canonical boundary conditions. In the second, a general algorithm based on equivalence principle for calculating Green's functions of canonical multi-layered structures will be shown.
15:40 The General EM Solver G2DMULT and Application to Analysis of New Developed Random-LOS Measurement Facility
Jian Yang (Chalmers University of Technology, Sweden)
G2DMULT is a general solver for antennas and electromagnetic problems that have almost two-dimensional geometries. The frame of the code G2DMULT was developed by Prof. Per-Simon Kildal. This paper reviews the principles and the developments of the code, and its new application to Ramdom-LOS measurement system which was proposed by Kildal, too.
16:00 Coffee Break
16:30 Research Collaboration on Waveguide Slot Array Antennas Between Prof. Kildal and Tokyo Tech
Jiro Hirokawa and Makoto Ando (Tokyo Institute of Technology, Japan)
This paper overviews the research collaboration on waveguide slot array antennas between Prof. Per-Simon Kildal and Tokyo Institute of Technology. Also, the development of the plate-laminated waveguide by Tokyo Tech is presented.
16:50 Reverberation Chamber for OTA Measurements: The History of a Dream!
Jan Carlsson (Provinn AB, Sweden); Christian Lötbäck (Bluetest AB, Sweden); Andrés Alayon Glazunov (Chalmers University of Technology, Sweden)
In the late 1990´s Professor Per-Simon Kildal got the idea that reverberation chambers could be used for characterizing small antennas and mobile devices. Many thought the idea was crazy but he was persistent and worked hard to realize his dream to build a small chamber that could be used by the wireless industry. This paper gives a short history of the research at Chalmers and the creation of the company Bluetest that both were instrumental for realizing the dream.
17:10 How Gap Waveguides Were Conceived
Alejandro Valero-Nogueira (Universidad Politécnica de Valencia, Spain); Esperanza Alfonso (Gapwaves AB, Gothenburg, Sweden)
In this paper the steps that led to gap waveguide conception are surveyed. Background, main physical property exploited and its implications are discussed. Nevertheless, applications resulting from the original idea are also reviewed.
17:30 Three Decades Journey from Real to Artificial with Kildal
Ahmed Kishk (Concordia University, Canada)
In memory of Professor Per-Simon Kildal, kishk presents an overview of the collaboration between them. It can be considered as a brief review of the subjects that were of mutual interest between them. Most of their work pointed toward simplification of complicated structures through the understanding of the physical meaning of boundary conditions. Kildal's contributions were directed towards commercial applications through his clear vision for the future. The paper tells a successful story of long-term collaborations between their research groups. Other research groups should be encouraged to follow such an example.
17:50 One Meter Deployable Reflectarray Antenna for Earth Science Radars
Nacer Chahat (NASA-JPL, Caltech, USA); Jonathan Sauder (NASA-JPL / Caltech, USA); Gregory Agnes and Thomas Cwik (NASA-JPL, Caltech, USA)
This paper describes the development of a 1-m deployable reflectarray antenna which is designed to fit in a 6U (10×20×30cm3) class CubeSats. It operates at 35.75 GHz for the measurement of atmospheric processes over a short, evolutionary timescale. It deploys into a 98.6 cm × 82.1cm flat reflector. This antenna provides a gain of 48.0 dBi and an aperture efficiency of 44%. It consists of a cassegrain reflectarray using 14 deployable panels, one fixed panel and a telescoping feed and subreflector. This paper is written in celebration of Per-Simon Kildal: a scholar, mentor and friend. Per-Simon's broad interests and delightful passion led him to the Jet Propulsion Laboratory and Caltech in Pasadena, CA many times over his career. Professionally, Per-Simon's work in multi-reflector antenna design and analysis developed for his work at the Arecibo Observatory influenced developments in the NASA/JPL Deep Space Network beam-waveguide antenna design. At the same time, his work on multi-reflector antenna synthesis and its associated asymptotic diffraction effects were seminal pieces of research that simplified the engineering design and construction of very large antennas. His brilliant and intuitive grasp of seamlessly connecting the theoretical to the practical is remarkable. Personally, Per-Simon's infectious curiosity and humorous nature led to productive interactions across nationalities and disciplines leading to collegial partnerships, teaching, mentoring and life-long friendships. This paper applies traditional concepts of reflectarray antennas to low-cost and innovative cubesat platforms for space-based remote sensing. It is dedicated to and inspired by Per-Simon's wonderful drive to innovate and find great solutions.
18:10 Closing of the Session in Memory of Prof. Per-Simon Kildal
Madeleine Schilliger Kildal (Chalmers University of Technology & Bluetest AB, Sweden)
This paper is dedicated to close the session in memory of Per-Simon Kildal. It will be presented by his daughter: Madeleine Schilliger Kildal.

### Monday, March 20, 14:00 - 16:00

#### R_M01 RCS Measurements

Radars / Regular Session / Measurements
Oral Sessions: Room 352A
Chairs: Jean-Michel Geffrin (Institut Fresnel & Aix Marseille Univ, CNRS, Centrale Marseille, France), Alexander Yarovoy (TU Delft, The Netherlands)
14:00 On the Interest of a Bistatic Radar Cross Section Setup to Measure Various Scattering Quantities
Jean-Michel Geffrin (Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France); Hassan Saleh (Centre Commun de Ressources en Microondes, Institut Fresnel, France); Christelle Eyraud (Institut Fresnel, Aix Marseille Université, CNRS, Centrale Marseille, France); Amélie Litman (Aix-Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, France)
This paper describes how the bistatic radar cross section (RCS) experimental setup of the "Centre Commun de Ressources en Microondes" (CCRM) was used to precisely determine various scattering quantities and how we took profit of the large scattering angular range available with this setup. Results on extinction cross section, linear degree of polarization and other scattering quantities of interest are presented. We also show how those results are interesting in different domains where scattering phenomena are studied thanks to the scale invariance properties of the Maxwell equations using the so called microwave analogy.
14:20 Bistatic Scattering Measurement on Low Permittivity Spheroidal Objects
Hassan Saleh (Centre Commun de Ressources en Microondes, Institut Fresnel, France); Jean-Michel Geffrin (Institut Fresnel & Aix Marseille Univ, CNRS, Centrale Marseille, France); Hervé Tortel (Institut Fresnel, Aix Marseille Université, CNRS, Centrale Marseille, France)
In this paper we present our advances in the scattering measurement of low electromagnetic signature objects. The targets under test are spheroids of low permittivities and of sizes compared to the wavelength. The measurements were carried-out at the experimental facility of the "Centre Commun de Ressources en Microondes" (CCRM) in bistatic configuration and using a hard-gating noise reduction system. The measurements were further assessed through comparisons to computations with Finite Element Method. Good agreement is reported.
14:40 Range Segmentation for micro-Doppler of Backscattered Field by Wind Turbines
Stefano Medagli (TU Delft); Oleg Krasnov (Delft University of Technology, The Netherlands); Alexander Yarovoy (TU Delft, The Netherlands)
In this paper, a simple electromagnetic model for wind turbine's backscattering is proposed. The wind turbine is modeled as a linear structure made of three rotating wires on which an electromagnetic fields impinges. Since a wind turbine is much bigger than typical radar range resolution cells, just a small part of it is involved in the backscattering for a single resolution cell. An analysis of the micro-Doppler features for each range cell involving the wind turbine is then proposed. The models are both compared and validated using real data acquired with PARSAX radar. The main features obtained from these models can be used to understand the backscattering mechanisms for a wind turbine and for developing of clutter mitigation algorithms.
15:00 RF Front End for UAS-Aided Flight Inspection of Airport Surveillance Radars
Jürgen Fitschen and Sebastian Koj (Leibniz Universität Hannover, Germany); Jochen Bredemeyer (FCS Flight Calibration Services GmbH, Germany); Heyno Garbe (Leibniz Universität Hannover, Germany)
Flight inspection of radio-based terrestrial navigation systems is crucial for sufficient accuracy. Especially in proximity of wind turbines (WT), flight inspections must be carried out. This causes problems that hinder the usage of conventional aircraft. To solve this problem, unmanned aerial systems (UAS), such as multicopters, are a promising approach. Beside the solution of the clearance problem, they also provide further benefits in terms of cost effectiveness and flexibility. Since commercial off-the-shelf (COTS) test receivers exceed the UAS's loading capabilities, we developed a weight- and size-optimized test receiver that can compete with full-compliance measurement COTS devices. This has been achieved by focusing on the demands regarding carrier frequency and bandwidth of the system under test (SUT). In this paper we describe the RF front end for the reception of the forward scatter emitted by the airport surveillance radar (ASR) and show the first measurement results.
15:20 Interlaboratory Comparisons of Radar Cross Section Measurements by the "GTi", Criteria Suggestions
Juan-Carlos Castelli (ONERA, France); Fabrice Comblet (ENSTA Bretagne, France); Franck Daout (GEA universite Paris 10, France); Christelle Eyraud (Institut Fresnel, Aix Marseille Université, CNRS, Centrale Marseille, France); Sylvie Fargeot (AIRBUS Defence and Space, France); Régis Guillerey (DGA, France); Jean-Michel Geffrin (Institut Fresnel & Aix Marseille Univ, CNRS, Centrale Marseille, France); Samuel Leman (NEXIO, France); Pierre Massaloux (CESTA, France); Genevieve Maze-Merceur (CEA, France); Gerard-Pascal Piau (EADS CCR, France)
A comparison of Radar Cross Section (RCS) measurement results between several French measurement indoor facilities has been organized in the framework of a French Working Group (Groupe de Travail sur les incertitudes en chambre anéchoïque: GTi), dealing with measurement uncertainties in anechoic chamber. The GTi involves 22 laboratories that are either industrial or academic research ones, or laboratories depending on public organisms. Three tasks have been defined: 1/ State of the art, 2/ Comparisons of RCS measurements, 3/ Comparisons of Antenna Measurements. This paper deals with the second task, in which 8 laboratories are engaged. The motivations and the tasks are described in this paper and results will be presented at the conference. Comparison criteria will also be proposed.
15:40 A Study of Aircraft Detection Using DTTB Signal Delay Profile
Takuya Otsuyama and Junichi Honda (Electronic Navigation Research Institute, Japan)
The current Air Traffic Management (ATM) uses a combination of several radar system. However, the conventional Primary Surveillance Radar (PSR) have a high cost of the operation in comparison with usage. Recently, Multi-Static Primary Surveillance Radar (MSPSR) has attracted interest from the civil aviation research field. The MSPSR system use not only the conventional radar signals but also other radio waves, such as Digital Terrestrial Television Broadcasting (DTTB). In this paper we described the experimental results of aircraft detecting by using DTTB signals and the potential of the aircraft detection by proposed method.

#### CS24 Measurements and Simulations in Channel Modelling in Wireless Body Area Networks (COST CA15104 IRACON)

Localization & Connected Objects / Convened Session / Propagation
Oral Sessions: Room 352B
Chairs: Slawomir J. Ambroziak (Gdansk University of Technology, Poland), Luis M. Correia (IST - University of Lisbon & INESC, Portugal)
14:00 UWB In-Body Channel Performance by Using a Direct Antenna Designing Procedure
Carlos Andreu (Institute of Telecommunications and Multimedia Applications, Spain); Concepcion Garcia-Pardo (Universitat Politècnica de València & Institute of Telecommunications and Multimedia Applications (iTEAM), Spain); Alejandro Fornes-Leal (Institute of Telecommunications and Multimedia Applications, Spain); Marta Cabedo-Fabrés (Universidad Politécnica de Valencia, Spain); Narcis Cardona (The Polytechnic University of Valencia, Spain)
UWB systems have been proposed as a candidate for the next generation of in-body applications. In order to perform reliable UWB channel measurements, implantable antennas should work in the propagation medium properly. To assess the UWB channel performance, in-body antenna matching should be assured. Besides, an omnidirectional radiation pattern in order to communicate with a sensor array located around the body should be achieved. This paper is devoted to the analysis of the UWB in- body channel when using an antenna miniaturization procedure that maintains its omnidirectional radiation pattern as well as its operation bandwidth. For that, an UWB monopole antenna with circular patch is directly miniaturized and optimized considering the human muscle tissue. To assess the impact of antenna miniaturization, the results of the channel propagation measurement campaign obtained with the miniaturized antenna are compared with those obtained from a larger UWB monopole in a previous measurement campaign.
14:20 Consideration of Antenna Directions for High Frequency Wireless Body Area Networks During Human Walking Movement
Takahiro Aoyagi (Tokyo Institute of Technology, Japan)
As increased requirements for much high speed and capacity telecommunications, frequency bands of wireless communications become higher such as millimeter wave or terahertz wave. In these high frequency bands, beam foaming is employed to gain stable connectivity. On-body body area network is one of fascinate application of these high capacity frequency bands. However, directions of on-body antennas largely fluctuates and shadowing frequently occurs due to human movements. In this paper, variation of antenna directions and shadowing of on-body propagation during human walk movement is investigated. As a result, range of antenna rotation and shadowing rate, which can be used future system design of high frequency body area networks, is clarified.
14:40 Composite Fading in Non-line-of-Sight Off-Body Communications Channels
Seong Ki Yoo (Queen's University Belfast, United Kingdom (Great Britain)); Simon Cotton (Queen's University, Belfast, United Kingdom (Great Britain))
In this paper, we investigate the characteristics of the composite fading observed in non-line-of-sight (NLOS) off-body communications channels using the $\eta$-$\mu$/inverse gamma distribution. We use a number of different datasets obtained from NLOS off-body measurements which have been performed in a range of different environments at 5.8 GHz and 60 GHz. In all cases, the bodyworn node was positioned on the front-central chest region of an adult male. It is shown that the $\eta$-$\mu$/inverse gamma model provides an excellent fit to the measurement data for all of the considered cases. Using the Akaike information criterion (AIC), we have compared the -/inverse gamma model with other composite and non-composite fading models associated with the NLOS channel conditions. The AIC results confirm that the $\eta$-$\mu$/inverse gamma model was the most likely model to have been responsible for generating the channel data from the set of candidates which were considered.
15:00 An Empirical Model for the Polarisation Characteristics of Indoor Off-Body Channels
Kenan Turbic (IST - University of Lisbon & INESC-ID, Portugal); Slawomir J. Ambroziak (Gdansk University of Technology, Poland); Luis M. Correia (IST - University of Lisbon & INESC, Portugal)
This paper presents an analysis of the polarisation characteristics for the channel in dynamic off-body communications, and an empirical channel model, based on measurements performed at 2.45 GHz in an office environment. Body presence and propagation conditions have a strong influence on signal depolarisation. The model assumes three components for the total path loss: mean path loss, represented by a log-distance function with a path loss exponent of 1.71, Lognormal-distributed shadowing fading, and Nakagami-distributed multipath fading. The Nakagami Distribution shows a trend towards the Rice one in the co-polarised and the Rayleigh one in the cross-polarised channels.
15:20 Key Generation Based on Fast Reciprocal Channel Estimation for Body-Worn Sensor Nodes
Patrick Van Torre, Quinten Van den Brande and Jo Verhaevert (Ghent University, Belgium); Jan Vanfleteren (Ghent University and IMEC, Belgium); Hendrik Rogier (Ghent University, Belgium)
With the advent of the Internet of Things, body-worn sensor nodes are continuously becoming more important. In case of bio-medical, rescue-worker or military applications sensitive data are often transmitted, requiring the need for encryption. Body-worn sensor nodes are generally employed in quickly varying channel conditions due to body movement. The radio-communication channel between such nodes is however reciprocal, allowing the extraction of an array of similar channel measurements at both ends of the link. These data can be used to build equal encryption keys at both link ends. This paper studies the practical performance of an enhanced channel-based key generation system with a very short round-trip delay. Measurements were performed using the new system and the results of the enhanced key generation are evaluated. Although the performance is slightly increased thanks to the shorter round-trip delay, the accuracy of the signal level detector still imposes limits.
15:40 Internet of Animals: On-and Off-body Propagation Analysis for Energy Efficient WBAN Design for Dairy Cows
Said Benaissa (Ghent University/iMinds, Belgium); David Plets (Ghent University - imec, Belgium); Emmeric Tanghe, Gunter Vermeeren and Luc Martens (Ghent University, Belgium); Bart Sonck, Frank Tuyttens and Leen Vandaele (Institute for Agricultural and Fisheries Research (ILVO), Belgium); Wout Joseph (Ghent University/IMEC, Belgium)
This paper presents propagation modelling of different on-body and off-body wireless communication scenarios for dairy cows in barns at 2.4 GHz. Based on the obtained propagation models, a WBAN that monitors multiple heath parameters is designed for optimal performances in terms of energy efficiency and packet error rate.

#### MT_A01 Integral Equations

Methods & Tools / Regular Session / Antennas
Oral Sessions: Room 353
Chairs: Elizabeth Bleszynski (Monopole Resesarch, USA), Francesca Vipiana (Politecnico di Torino, Italy)
14:00 Reduction of Singular Surface Integrals to Non-Singular Line Integrals in Integral Equations Involving Non-Parallel Surface Elements
Elizabeth Bleszynski (Monopole Resesarch, USA); Marek Bleszynski, Dr (Monopole Resaearch, USA); Thomas Jaroszewicz (Monopole Research, USA)
A novel procedure is presented for the evaluation of matrix elements of the tensor Green function with Rao-Wilton- Glisson basis functions appearing in surface integral equations in electromagnetics. The procedure,contitutres the generalization of our previous result to non-planar geometries, reduces four- dimensional surface integrals with singular integrands to line integrals over triangle edges with regular integrands. The main advantage of the derived expressions is that they offer simplicity and easily controllable accuracy achieved at a computational cost significantly lower than for previously considered techniques, in particular the conventional singularity subtraction method.
14:20 Acceleration of 4-D Reaction Integrals in the Method of Moments via Double Application of the Divergence Theorem and Variable Transformations
Javier Rivero (Istituto Superiore Mario Boella, Italy); Francesca Vipiana (Politecnico di Torino, Italy); Donald Wilton (University of Houston, USA); William Johnson (New Mexico Institute of Mining and Technology)
In this paper we propose a scheme to treat, as a whole, the 4-D reaction integrals appearing in the Method of Moments. The surface divergence theorem is twice applied directly in the physical space domain, thus eliminating restrictions to well-shaped, touching elements required by mapping to an angle-distorting normalized coordinate system together with an appropriate integration reordering. The resulting 4-D surface integral is expressed as two radial integrals plus two contour integrals over source and observation domain boundaries. The radial integrals significantly smooth the kernel, and the resulting contour integrals are further regularized for efficient numerical evaluation.
14:40 Nonconforming Discretization of the PMCHWT Integral Equation Applied to Arbitrarily Shaped Dielectric Objects
Ivan Sekulic and Eduard Ubeda (Universitat Politècnica de Catalunya (UPC), Spain); Juan M. Rius (Universitat Politècnica de Catalunya, Spain)
The Poggio-Miller-Chan-Harrington-Wu-Tsai (PMCHWT) integral equation is widely used in the scattering analysis of dielectric bodies. The RWG set is normally adopted to expand the electric and magnetic currents in the Method of Moments (MoM) discretization of the PMCHWT formulation. This set preserves normal continuity across edges in the expansion of currents. However, in the analysis of composite objects, the imposition of such continuity constraint around junctions, where several regions intersect, becomes convoluted. We present a new nonconforming discretization of the PMCHWT formulation so that currents are expanded with no continuity constraint across edges. This becomes well-suited for the analysis of composite objects or nonconformal meshes, where some adjacent facets have no common edges. We show RCS results where the nonconforming PMCHWT implementation, facet-oriented, shows similar or better accuracy as the conventional approach, edge-oriented, for a given degree of meshing.
15:00 Enhanced MoM for the Analysis of Multilayered Periodic Structures Containing Dipoles with Application to the Design of Reflectarray Antennas
Rafael Florencio (Universidad de Sevilla, Spain); Rafael R. Boix (University of Seville, Spain); Jose A. Encinar (Universidad Politecnica de Madrid, Spain); Giovanni Toso (European Space Agency, The Netherlands)
The spectral domain Method of Moments (MoM) is customarily used in the analysis of multilayered periodic structures. In this paper a hybrid MoM is introduced for the analysis of multilayered periodic structures containing sets of dipoles at two metallization levels. In the hybrid MoM the matrix entries involving basis functions of dipoles at different metallization levels are computed in the spectral domain. However, the matrix entries involving basis functions at the same metallization level are computed in the spatial domain. The implemented hybrid MoM is applied to the design of multilayered reflectarray antennas made of dipoles under the local periodicity assumption. Thanks to the use of interpolated expressions for the periodic spatial Green's functions in terms of both coordinates and incidence angles, the CPU time required by the hybrid MoM in the design of the antennas is around twenty times faster than that required by the spectral domain MoM.
15:20 Locally Corrected Nyström Technique and Its Relationship with RWG Method of Moment for Current Reconstruction Using Very-Near-Field Measurements
Rezvan Rafiee Alavi (University of Alberta); Ali Kiaee, Rashid Mirzavand and Pedram Mousavi (University of Alberta, Canada)
The Locally corrected Nyström (LCN) method is used for current reconstruction on the surface of microwave boards and antennas. A relationship is established between LCN and RWG method of moment (MoM) for this application to enforce current continuity. This approach allows designers to find, characterize, and address the cause of a design failure in a microwave board or an antenna under test. The advantage of this method over the conventional method of moment (MoM) is that as a point-based approach efficiency can be enhanced in its acceleration with the multilevel fast multipole algorithm (MLFM).
15:40 Reduction of Volume-Volume Integrals Arising in Galerkin JM-VIE Formulations to Surface-Surface Integrals
Ioannis Georgakis and Athanasios Polimeridis (Skolkovo Institute of Science and Technology, Russia)
The numerical evaluation of current-based volume integral equation formulations typically involves 6-D integrals with kernels that exhibit strongly singular or weakly singular behavior when observation points coincide with source points.We demonstrate that these integrals can be reduced to 4-D integrals with smoother kernels that are amenable to numerical evaluation by means of well-established numerical schemes originally developed for surface integral equation formulations.

#### CS01 A Century After Tesla: How Far Have We Come With Wireless Power Transfer ?

Future Applications / Convened Session / Antennas
Oral Sessions: Room 362/363
Chairs: Yi Huang (University of Liverpool, United Kingdom (Great Britain)), Huib J. Visser (IMEC Netherlands, The Netherlands)
14:00 A Brief History of Radiative Wireless Power Transfer
Hubregt J. Visser (imec The Netherlands, The Netherlands)
The position of radiative Wireless Power Transfer (WPT) in the spectrum of power harvesting is given and a brief history of radiative WPT, starting with the work of Faraday is presented. The challenges in increasing the received dc power level or the transfer distance are outlined and possible directions for a solution are indicated.
14:20 Far Field WPT - Main Challenges
Daniel Belo (Universidade de Aveiro & Instituto de Telecomunicações, Portugal); Nuno Borges Carvalho (University of Aveiro/IT Aveiro, Portugal)
In this paper the main challenges that far field wireless power transmission should deal with will be presented and discussed. New developments made in Aveiro University in order to solve some of the issues raised will also be discussed, those include the use of special design waveforms, special design of antennas for WPT and also alternatives for WPT RF-DC conversion efficiency.
14:40 Light-Weight Wireless Power Transfer for Mid-Air Charging of Drones
Paul Mitcheson, Samer Aldhaher, David Christopher Yates, George Kkelis and Juan Arteaga (Imperial College London, United Kingdom (Great Britain))
Recent developments in inductive wireless power transfer (WPT) mean that the technology has reached a point where powering small drones has become feasible. Fundamentally, drones can only carry limited payloads and thus require light-weight WPT receiver solutions. The key to achieving light weight is operating the WPT system at high frequency: this allows both the coils and the electronics to achieve very high power densities. When operated in the MHz region, the WPT coils can be manufactured without the need for ferrite, because the low coupling factor can be offset by very high coil Q factors. To make efficient MHz power conversion circuits, wide band-gap semiconductors, including SiC and GaN have provided a step change. For powering a drone, these devices are integrated into soft-switching resonant inverter and rectifier topologies and are able to operate efficiently at tens of MHz.
15:00 Recent Advances in Broadband Rectennas for Wireless Power Transfer and Ambient RF Energy Harvesting
Chaoyun Song, Yi Huang and Jiafeng Zhou (University of Liverpool, United Kingdom (Great Britain)); Paul Carter (Aeternum, LLC, USA)
Wireless energy harvesting from ambient electromagnetic fields is becoming an emerging technology that can be exploited as a power source for many low power electronic devices. A number of key challenges are identified but the optimum design of rectennas for ambient WEH is very challenging. This paper presents a review on recent progress in multiband and broadband rectennas for WEH and wireless power transfer and introduces the latest research on this topic at the University of Liverpool, UK. In addition to the existing technologies, we have developed a number of novel techniques to develop rectennas with a simple structure, a broad bandwidth and an improved RF-DC conversion efficiency. Moreover, our rectennas can achieve consistent performance for a dynamic input power level or a wide load impedance range. The state-of-the-art technologies presented in this paper could have a great impact on the future development of rectennas for many related applications.
15:20 RF-Powered, Backscatter-Based Cameras
Saman Naderiparizi, Zerina Kapetanovic and Joshua R. Smith (University of Washington, USA)
RF-powered devices equipped with general-purpose microcontrollers face energy limitation constraints for performing arbitrarily complex sensing/computation tasks. While richer capabilities such as image capture and processing would enable many new RF-powered use-cases, this energy limitation narrows the application space. Enabling richer sensing tasks has two main challenges: efficiently retaining harvested energy, and storing/communicating large quantity of sensor data. This paper reviews the WISPCam design, an RF-powered programmable camera. WISPCam integrates an off-the-shelf VGA camera which is a rich sensor example energy and data wise. The paper also presents an ultra-low power scheme that is able to provide periodic updates on charge state of the device before enough energy has been accumulated for image capture. This paper presents a novel data storage and bi-directional communication scheme that enables reliable transfer of complete images to an RFID reader application even when packets are lost or the device runs out of energy.
15:40 Study on 5.8 GHz Single-Stage Charge Pump Rectifier for Internal Wireless System of Satellite
Ce Wang and Naoki Shinohara (Kyoto University, Japan); Tomohiko Mitani (Kyoto Universiy, Japan)
For reducing the weight of a satellite, an internal wireless system of satellite is proposed in a previous study. It is a system that can communicate between the subsystems of a satellite by carrying wireless communication modules. In this paper, we propose a complete internal wireless system of satellite with microwave wireless power transmission technology, and designed a 5.8 GHz highly efficiency rectifier circuit based charge pump circuit, and introduced a class-F load. We compared the rectifying efficiency of single shunt rectifier and charge pump rectifier theoretically, the conclusion is that they should have the same conversion efficiency, and this result are verified by experiment. The conversion efficiency increase to 78 % at 30 mW in the simulation, and obtained about 71 % conversion efficiency in the experiment. In addition, the output voltage is higher than 5 V at optimum load.

### Monday, March 20, 16:30 - 18:30

#### CS08 Advances on Transformation Electromagnetics Based Antennas

Future Applications / Convened Session / Antennas
Oral Sessions: Room 341
Chairs: Shah Nawaz Burokur (LEME, France), Anne-Claire Lepage (Institut Mines-Telecom, Telecom ParisTech, France)
16:30 Beam Squinting Metalens Design and Its Application to Multibeam Reflector Feeds
Mario Mencagli, Jr., Francesco Caminita and Enrica Martini (University of Siena, Italy); Patrizio De Vita (IDS Ingegneria Dei Sistemi, Italy); Valentina Sozio (Istituto Superiore Mario Boella, Italy); Marco Sabbadini (Esa Estec, The Netherlands); Stefano Maci (University of Siena, Italy)
This contribution presents the design of a metalens providing a desired beam squint with negligible reflections. This devices is applied at the mouth of a conical horn with the objective to obtain a squinted beam feed, that is advantageous in multibeam antenna applications. The metalens consists of three metallic layers, whose constituent elements are chose so as to provide all the required impedance values with smooth variations across the horn aperture. Full wave results are reported to validate the design.
16:50 Broadband Metasurface Luneburg Lens Antenna Based on Glide-Symmetric Bed of Nails
Kexin Liu, Fatemeh Ghasemifard and Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden)
A broadband metasurface Luneburg lens based on glide-symmetric bed of nails is designed. First, the Luneburg lens was re-shaped using quasi-conformal transformation optics. With this technique, the original circular focal curve of the lens is changed to a straight line. Afterwards, the refractive index distribution of the optically transformed lens is realized by changing the height of the pins in a bed of nails configuration. The complete Luneburg lens is simulated in CST Microwave Studio and the results demonstrate that the lens has 8-16 GHz bandwidth.
17:10 Scattering Free Graded Index Profiles and the Control of Electromagnetic Fields
Benjamin Vial (Queen Mary, University of London, United Kingdom (Great Britain)); Yangjie Liu (Nanyang Technological University, United Kingdom (Great Britain)); Simon Horsley and Thomas Philbin (University of Exeter, United Kingdom (Great Britain)); Yang Hao (Queen Mary University, United Kingdom (Great Britain))
We present a general methodology to arbitrarily manipulate the amplitude and phase of an electromagnetic wave propagating in a two-dimensional medium, without introducing any scattering. This leads to a class of isotropic spatially varying permittivity and permeability profiles that are transparent to an incident plane wave while shaping the field magnitude. Furthermore, we propose a metamaterial structure working in the infrared that demonstrates deep sub-wavelength control of the electric field amplitude and strong reduction of the scattering.
17:30 Transformation Electromagnetics and 3D Printing: Devices for Novel Antenna Solutions
Jianjia Yi (Xidian University, P.R. China); André de Lustrac (Institut d'Electronique Fondamentale - Université Paris-Sud, France); Gerard-Pascal Piau (EADS CCR, France); Shah Nawaz Burokur (LEME, France)
Transformation Electromagnetics is applied to design electromagnetic devices for focusing and collimating applications at microwave frequencies. Three devices are studied and conceived by solving the Laplace's equation that describes the deformation of a medium in a space transformation. Prototypes are fabricated using low-cost dielectric 3D printing technology. The first device is used to compensate for the curvature of a non-planar antenna array, the second one is applied to steer an electromagnetic beam and the last one is used to taper the flow of an electromagnetic field. These devices can find potential applications in novel antenna concepts.
17:50 Transformation Electromagnetics Enabled Lens Design with Surrogate-Assisted Global Optimization
John Easum, Jogender Nagar and Sawyer D Campbell (The Pennsylvania State University, USA); Douglas H Werner and Pingjuan Werner (Pennsylvania State University, USA)
A gradient index lens is designed by utilizing quasi-conformal transformation electromagnetics (qTEM) to define the index distribution in a rotationally symmetric lens. The smooth and continuous nature of qTEM is investigated and an analytical surrogate model is trained to replace the computationally intensive qTEM procedure and ray trace simulations. The surrogate model is then incorporated into an optimization strategy which is able to converge to an optimal design in substantially fewer function evaluations than a traditional global optimization scheme.
18:10 Ultra-thin Metalens for Multibeam Emission Based on Transformation Optics
Kuang Zhang, Guohui Yang, Xumin Ding, Meng Fan-Yi, JiaHui Fu and Wu Qun (Harbin Institute of Technology, P.R. China)
A general design of metalenses for N-beam emissions is proposed based on transformation optics. A linear transformation mapping is adopted to achieve the homogeneous characterization of the transforming medium, which is therefore easy to be fabricated compared with previously designs limited by inhomogeneity based on transformation optics. To verify the theoretical design, a four-beam antenna constructed with ultrathin, homogenous and uniaxial anisotropic metalens is designed, fabricated and measured. It is shown that the realized gain of the four-beam antenna is increased by 6 dB compared with the single dipole source, while working frequency and relative bandwidth are kept unchanged. The measured far-field pattern verifies theoretical design procedure.

#### C_M02 Measurement Topics

Cellular Communications / Regular Session / Measurements
Oral Sessions: Room 342A
Chairs: Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany), Brett Walkenhorst (NSI-MI Technologies, USA)
16:30 Thermal Noise Effects of a Simple Correlator for High Dynamic Range Measurements
Brett Walkenhorst (NSI-MI Technologies)
In order to achieve high accuracy in measuring sidelobes and/or nulls in antenna patterns, it is necessary to use a test system with very high dynamic range. For several years, commercially available antenna measurement receivers have offered a dynamic range as high as 135dB for such applications. This dynamic range has been made possible, in part, by a simple correlator in the receiver's DSP chain. In a previous paper, noise-free signal models were developed and analyzed to demonstrate the correlator's ability to reduce carrier frequency offset (CFO) and local oscillator (LO) phase noise to offer the fidelity of test signal necessary to achieve extremely high dynamic ranges of up to 135dB. Building on those models, this paper models the effects of thermal noise and analyzes situations where the correlator works well and where it negatively impacts performance.
16:50 Inverse-Source Algorithm for Antenna-Field Transformations Using the Weak Form of the Combined-Source Condition
Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany); Thorkild Birk Hansen (Seknion, Inc., USA)
Inverse equivalent-source algorithms for antenna field transformations are particularly powerful and robust if they work with directive sources that radiate primarily from the source region towards the field observation locations. Such directive behaviour can for example be achieved by employing an additional integral equation that explicitly imposes a null-field condition (known also as a Love condition) in the original source region of the antenna. An approximate null-field condition can be achieved in the form of an impedance-boundary condition, which is also known as the combined-source condition. In this work, the combined-source condition is utilized in a weak form, and the directivity of the expansion sources is further increased by shifting the source points into complex space. This inverse source algorithm is formulated and used for near-field to farfield transformations of measured antenna fields. The results are discussed and compared to those achieved with the corresponding strong-form algorithm.
17:10 Analysis of Electromagnetic Measurements in Intercomparisons with Low Number of Participants
Isabel Expósito (University of Vigo, Spain); Manuel García Sánchez (Universidade de Vigo, Spain); Iñigo Cuiñas (University of Vigo, Spain)
The evaluation of performance represents a critical activity to ensure the quality standards of electromagnetic test labs. Intra- and inter-laboratory measurement campaigns are used for that purpose. However, problems arise when a low number of participants take part in the comparison. We present several intercomparison examples and the difficulties that appear in the data analysis.
17:30 A New One-Port S-Parameter Calibration Workflow by Means of a MEMS-based Variable Capacitor Array
Manuel Kasper, Mykolas Ragulskis and Ivan Alic (Keysight Technologies, Austria); Jorgen Bojer (Wispry Inc., Denmark); Michael Dieudonné (Keysight Technologies, Belgium); Ferry Kienberger (Keysight Technologies, Austria)
One-port reflection calibration is a widely used technique for RF and microwave VNA measurements in a broad range of applications including on-wafer chip testing, production testing, and microwave imaging. Recent developments in the field of antenna tuning components lead to advanced, highly stable MEMS-based variable capacitors. In this study we present the use of an antenna tuning integrated circuit (IC) for realizing a compact and fast transfer standard for one-port calibration. In contrast to traditional Short-Open-Load methods a new workflow that uses different capacitance states was developed. Together with least-squared-error solving this leads to improved calibration performance. Verification against metrology grade standards showed agreement of less than -45 dB vector difference. In addition, an estimation of the expected S-parameter error due to temperature deviations was performed. The new calibration workflow can be used in applications where multiple ports need to be calibrated fast and accurate.
17:50 SVO in Array Diagnostic for the Planar Near-Field Scanning
Amedeo Capozzoli, Claudio Curcio and Angelo Liseno (Università di Napoli Federico II, Italy)
A method for the array characterization from Near-Field measurements is here presented. The method exploit the concept of Singular-Value Optimization to dramatically reduce the number of data needed by a complete mapping of the excitations. The approach is here applied to a planar scanning and numerically validated.
18:10 NFC/RFID Benchmark Design and Verification Strategy Against EMVCo Standard
Yehya Nasser (L'Institut National des Sciences Appliquées de Rennes, France); Hussein Hijazi (Grenoble-INP, GIPSA-Lab, France); Ali Chamas Al Ghouwayel (Lebanese International University, Lebanon)
In this paper, the problem of NFC/RFID technology frontend performance verification is addressed. To make this technology succeeded, it is necessary to test conformance, acceptance, compliance, consistency and interoperability of NFC/contactless infrastructure. Industry bodies such as EMVCo is developing and maintaining programs to ensure device conformance, acceptance, compliance, consistency, and interoperability. Thus, a Test Bench Simulator is proposed, based on a Computer Aided Design tool, which allows flexible, fast and accurate verification strategy for NFC technology designs against complete test plans that are fully compliant with EMVCo NFC/contactless experimental specifications. To verify the proposed design, simulations are carried out and results are compared to the results of particular measurements done by the EMVCo laboratories. All results show a pretty good matching with EMVCo standard. Additionally, in this paper, simulation is conducted using full-wave 3D FEM EM Simulator.

#### B_P03 Biological Propagation Measurements

Biomedical / Regular Session / Propagation
Oral Sessions: Room 342B
Chairs: Caterina Merla (ENEA SSPT Division of Health Protection Technologies, Italy), Carey Rappaport (Northeastern University, USA)
16:30 Dosimetry and Hyperthermia Computation in Human Tissues in Presence of EM-Waves Using TLM Method
Abdelrahman Ijjeh (University of Nice Sophia-Antipolis & TELECOM Bretagne Institute, France); Oualid Makhlouf (University of Nice Sophia Antipolis & Laboratoire d'Electronique, Antennes et Télécommunications, France); Marylène Cueille (University of Nice Sophia Antipolis CNRS, France); Jean-Lou Dubard (Université de Nice - Sophia Antipolis, CNRS, France); Michel Ney (TELECOM Bretagne Institute, France)
The interaction between electromagnetic waves and complex media and its consequences on other physical phenomena such as hyperthermia is a crucial issue for various types of applications. To name a few, electromagnetic compatibility, microwave ovens design, medical applications, and the design of electromagnetic devices and circuits that include lossy media. In this article, we present a full-wave time-domain TLM-based framework that can handle electromagnetic, thermal and the electromagnetic-thermal coupling scenarios. Some experiments are presented and their results are compared with FIT (Finite Integration Technique).
16:50 Continuous Monitoring of Hemorrhagic Brain Strokes via Contrast Source Inversion
Ismail Dilman (Istanbul Technical University, Turkey); Uğur Yıldırım (Turkish-German University, Turkey); Egemen Bilgin, Semih Dogu, Mehmet Çayören and Ibrahim Akduman (Istanbul Technical University, Turkey)
We consider the differential microwave imaging for continuous monitoring of hemorrhagic brain strokes where our aim is to determine the change of bleeding in sequential time frames. The scattered electromagnetic field is measured in two different time steps, and the difference in the scattered field is used as the data of the inversion scheme. The imaging is performed via contrast source inversion. However, since the data of the inversion scheme consists of the difference of the scattered field measurements, the algorithm produces a differential contrast function instead of a complete reconstruction. This function carries information about the difference in the electromagnetic parameters of the brain, that is the relative size of the blood region, between two measurements. The numerical simulations with a realistic head model demonstrate that the method is capable of detecting changes in multiple blood regions, and provides information about the locations and the types of these changes.
17:10 Electromagnetic Exposure Systems for Real Time CARS Imaging
Caterina Merla (ENEA SSPT Division of Health Protection Technologies, Italy); Micaela Liberti (ICEmB at "Sapienza" University of Rome, Italy); Paolo Marracino (Sapienza University of Rome, France); Antoine Azan (CNRS UMR 8203, Laboratory of Vectorology and Anticancer Therapy, France); Francesca Apollonio (University Sapienza of Rome, Italy); Lluis Mir (CNRS UMR 8203, Laboratory of Vectorology and Anticancer Therapy, France)
We have developed an optical imaging technique based on the Coherent Anti-Stokes Raman Scattering (CARS) that is going to be used as a way to experimentally explore specific signatures (molecular scale) related to the electromagnetic exposure of single cells. This new experimental configuration combines a wide-field CARS microscope with a wide-band electromagnetic micro-device capable of simultaneously exposing several cells to various electromagnetic waveforms (pulsed or continuous waves). The numerical analyses conducted on three different micro-devices (an edge coupled microstrip line, a coplanar waveguide and a slot line) possibly suitable to be integrated into the CARS microscope are presented.
17:30 Alternating FDFD and Born Approximation to Compute Dielectric Properties of Breast Tissue and Localize Anomalous Lesions Using DBT Priors
Matthew Tivnan (Northeastern University & L2S, CNRS-CentraleSupélec, USA); Carey Rappaport (Northeastern University, USA)
A hybrid technique using Digital Breast Tomosynthesis and Microwave Tomography shows promise for improved contrast with respect to conventional breast imaging modalities. A healthy background field is modeled using a Finite Difference solver with prior geometry given by Digital Breast Tomosynthesis. This background field is subtracted from the measurements to isolate the anomalous portion of the measured signal which is due to the carcinoma. The healthy background geometry used in this simulation is obtained using a characteristic relationship between the mass attenuation coefficient (measured in X-ray images) of healthy tissue and the complex dielectric constant. This relationship can be computed using gradient descent. However, the computationally demanding nature of this inverse problem makes it less desirable for real clinical applications. Proposed herein is an algorithm which uses Born approximation on alternate iterations to decrease computational demand. Preliminary 2D numerical experiments in realistic media show this adjustment decreases the computation time.
17:50 Time Domain Complex Radar Cross Section of Human Body for Breath-Activity Monitoring
Tien Tu Vo (Telecom ParisTech, University of Paris-Saclay & CEA LETI Grenoble, France); Laurent Ouvry (CEA-Leti Minatec, France); Alain Sibille (Telecom ParisTech, France)
The knowledge of the complex Radar Cross Section (RCS) of the human body in ultra-wide band can fully describe the breathing activity. In this paper, we investigate the time domain RCS so as to analyze the backscattered signal from the human body, for further respiratory monitoring in any aspect angle. The time domain RCS measurements are first calibrated with the monostatic radar measurement of a metallic sphere. Subsequently, the RCS of a human body phantom is measured over the full 0-360o angle, azimuth range, allowing to put forward the creeping wave around the body. Finally, we measure the RCS of a human person and its temporal variation, also in various aspect angles. The results, which show a mixture between breathing and other body movements, are valuable inputs for respiratory monitoring in various body postures.
18:10 Bio-Electromagnetic THz Propagation Modeling for In-Vivo Wireless Nanosensor Networks
Hadeel Elayan (Khalifa University, United Arab Emirates); Raed Shubair (Massachusetts Institute of Technology (MIT), USA); Josep M Jornet (University at Buffalo, USA)
Nanosized devices operating inside the human body open up new prospects in the healthcare domain. In vivo wireless nanosensor networks (iWNSNs) will result in a plethora of applications ranging from intrabody health-monitoring to drug delivery systems. With the development of miniature plasmonic signal sources, antennas and detectors, wireless communications among intrabody nanodevices will expectedly be enabled in the Terahertz Band (0.1-10 THz). This result motivates the analysis of the phenomena affecting the propagation of electromagnetic signals inside the human body. In this paper, a rigorous channel model for intrabody communication in iWNSNs is developed. The total path loss is computed by taking into account the combined effect of the spreading of the propagating wave, molecular absorption from human tissues, as well as scattering from both small and large body particles. The overall attenuation model of intrabody THz propagation facilitates the accurate design and practical deployment of iWNSNs.

#### CS23 Massive MIMO Antenna Technologies and Interference Mitigation Techniques for 5G Networks in the Frequency Bands above 6 GHz

High Data-rate Transfer / Convened Session / Antennas
Oral Sessions: Room 343
Chairs: Przemyslaw Gorski (ViaSat, Switzerland), Rudolf Zetik (Fraunhofer Institute for Integrated Circuits IIS, Germany)
16:30 Antenna Array Configurations for Terrestrial Backhaul Links At Ka-band Frequencies
Rudolf Zetik (Fraunhofer Institute for Integrated Circuits IIS, Germany); Christian Steinmetz (Fraunhofer Institute for Integrated Circuits (IIS), Germany); Marcus Grossmann and Markus Landmann (Fraunhofer Institute for Integrated Circuits IIS, Germany); Giovanni Del Galdo (Fraunhofer Institute for Integrated Circuits IIS & Technische Universität Ilmenau, Germany)
The paper considers a backhaul network for Ka-band. In this band, antenna arrays must employ large number of elements with appropriate beamforming techniques to combat the severe path loss. The goal of this paper is to analyze massive antenna arrays under realistic considerations for the use in terrestrial backhaul links. This analysis addresses practical issues from the implementation point of view such as 3D array geometry, the minimum number of radiating elements needed to fulfill link budget requirements in backhaul links, distribution of radiating elements in a 3D array geometry and influence of realistic antenna patterns on beamforming capabilities of such arrays. The results indicate that a realistic backhaul scenario may require antenna arrays containing thousands of radiating elements. Selected simulation examples show that polarimetric beamforming is required in realistic scenarios especially when radiating elements do not have good cross polarization discrimination.
16:50 Developments on Phased Array for Low-Cost, High Frequency Applications
Przemyslaw Gorski (Viasat Antenna Systems SA); Maria Carolina Vigano (Viasat Antenna Systems SA, Switzerland); Daniel Llorens (ViaSat Antenna Systems SA, Switzerland)
This work presents the design and implementation of a phased array antenna for reconfigurable 5G backhaul network links. In order to minimize costs, the antenna has been developed using low cost RO4003 substrates and off the shelf electronic components. The antenna operates in Ka band (19 GHz) with scan range down to 50°.
17:10 Null-Steering Reflectarrays for 5G Backhaul Networks Limited by Interference
Xavier Artiga (Centre tecnològic de Telecomunicacions de Catalunya (CTTC), Spain)
Future 5G backhaul networks in dense small cell deployments will require high gain antennas with beam- and null-steering capabilities. In this framework this paper analyzes the null-steering capabilities of reflectarray antennas, as a low cost alternative to traditional antenna arrays. In particular, a random search algorithm is used to show that null-steering can be performed even with 1-bit reflectarrays, but that the synthesized null-depth and width is much more sensitive to aperture phase errors than the main beam gain. Multi-feed reflectarrays are then proposed to overcome this sensitivity but at the expense of higher system complexity and cost.
17:30 Low-Cost Hybrid Analog-Digital Beamformer Evaluation in Spectrum Sharing Systems
Miguel Ángel Vázquez (Centre Tecnològic de les Telecommunicacions de Catalunya (CTTC/CERCA), Spain); Xavier Artiga (Centre tecnològic de Telecomunicacions de Catalunya (CTTC), Spain); Ana Pérez-Neira (CTTC, Spain)
This paper evaluates different analog-digital beamforming solutions for future spectrum sharing mm-wave scenarios. In contrast to sub-GHz multiantenna schemes where all-digital solutions provide an excellent performance-cost trade-off, in the mm-wave bands where a very large number of antennas is required, all-digital designs cannot be deployed due to their cost and complexity. In order to solve this problem, sub-array solutions are conceived where a reduced number of radiofrequency chains are simultaneously connected to different antennas through an analog beamforming network formed by phase shifters (i.e. with no amplitude control). Different connectivity solutions are evaluated; namely, full-connected, localized and interleaved considering that either the phase shifters have full resolution or only one control bit. As reported in the paper, while for the full resolution case the same performance is obtained for all three connectivity schemes, in case the phase shifters have one control bit, substantial differences show up.
17:50 Real-field Performance of Hybrid MISO Time Reversal Multi-beam Beam-former at mm-Waves
Diego Dupleich (Ilmenau University of Technology, Germany); Stephan Haefner (Technische Universität Ilmenau, Germany); Robert Müller (TU Ilmenau, Germany); Christian Schneider (Ilmenau University of Technology, Germany); Jian Luo (Huawei Technologies Duesseldorf GmbH, Germany); Reiner S. Thomä (Ilmenau University of Technology, Germany)
In the present paper we evaluate the performance of a hybrid digital/analog multi-beam beam-forming architecture with polarization and delay compensation using time reversal (TR). Double-directional, ultra wideband dual-polarized channel measurements at 70 GHz in a conference room have been used to emulate the channel. The use of multiple beams to mitigate human shadowing has been evaluated and the temporal and spatial focusing of time-reversal to reduce inter-user interference.
18:10 Partial Update of Antenna Weight in Multiuser MIMO for Time-Variant Propagation Channel
Tetsuki Taniguchi (University of Electro-Communications, Japan); Yoshio Karasawa (No Affiliation, Japan); Nobuo Nakajima (The University of Electro-communications, Japan)
The performance of multiuser multiple input multiple output (MIMO) downlink communication system is degraded under the assumption of rapid movement of user terminals with a certain speed. Though several methods have been proposed to improve this situation, they consume extra-degrees of freedom for the extension of the zero forcing (ZF) area and/or heavy computational load for the frequent update of weights. This paper presents a low computational design approach based on block diagonalization consuming degrees of freedom smaller than or equal to the minimum required value, where only a subset of transmit weights are updated according to linearly extrapolated channel keeping the zero forcing condition as possible. Computer simulations exhibit that the proposed approach can always show good performance if the adequate weight update parameters are chosen.

#### R_A02 Antennas for Imaging

Radars / Regular Session / Antennas
Oral Sessions: Room 352A
Chairs: Valeri Mikhnev (Institute of Applied Physics, National Academy of Sciences, Belarus), Stefania Monni (TNO Defence Security and Safety, The Netherlands)
16:30 Performance Comparison of Different Sparse Array Configurations for Ultra-Wideband,Near-field Imaging Applications
Talat Cetin (Aselsan, Turkey); Lale Alatan (METU, Turkey)
The aim of this study is to compare the performance of different multiple-input multiple-output (MIMO) array topologies, intended to be used in ultrawideband (UWB) near-field imaging applications, by using an analysis method that does not include the effects of image reconstruction algorithm. For this purpose, maximum projection method, previously proposed for the analysis of UWB arrays under far-field conditions, is utilized and modified to obtain two way beam patterns of UWB arrays operating in the near-field. The side lobe levels of these beam patterns are shown to be a clear performance criterion for evaluating the performance of sparse antenna arrays. Numerical simulation results are compared with previously reported results for some commonly used array configurations and a good agreement is observed.
16:50 Near and Far Field Focusing Patterns for a 2D Sparse MIMO Array
Harun Cetinkaya and Simon Kueppers (Fraunhofer-FHR, Germany); Reinhold Herschel (Fraunhofer FHR, Germany); Nils Pohl (Ruhr-University Bochum & Fraunhofer FHR, Germany)
A geometrically simple circular array topology for two dimensional (2D) sparse multiple-input-multiple-output (MIMO) array is proposed. The focusing and imaging properties of the array in the millimeter-wave range with narrow-bandwidth are studied by simulation. The results for the focusing property show that the array has decent sidelobe levels over a wide field of view within near and far field. Imaging capability of the array presents that point-like targets are well reconstructed with a high dynamic range.
17:10 Broadband Coaxial Line to Rectangular Waveguide Transition for a Microwave Tomography Sensor
Malte Mallach and Thomas Musch (Ruhr-Universität Bochum, Germany)
A broadband coaxial line to rectangular waveguide transition for a microwave tomography sensor is presented. It consists of two parts: a coaxial line to double ridged waveguide transition and a double ridged to rectangular waveguide transformer. The transition is well matched (reflection coefficient below -10 dB) and has a low insertion loss (below 3 dB) in a wide frequency range from approximately 0.85 GHz to 4.4 GHz. Due to the symmetric design of the double ridged waveguide, a large single mode propagation bandwidth (0.6 GHz to 3.2 GHz) and a good higher order mode suppression (greater than 10 dB above 3.2 GHz) is achieved. The transition design is described in detail, analyzed by 3D electromagnetic field simulations, and validated by measurements.
17:30 High-resolution Imaging and Separation of Multiple Pedestrians Using UWB Doppler Radar Interferometry with Adaptive Beamforming Technique
Motoshi Anabuki and Shigeaki Okumura (Kyoto University, Japan); Takuya Sakamoto (University of Hyogo & University of Hawaii at Manoa, Japan); Kenshi Saho (Toyama Prefectural University, Japan); Toru Sato (Kyoto University, Japan); Mototaka Yoshioka (PANASONIC, Japan); Kenichi Inoue, Takeshi Fukuda and Hiroyuki Sakai (Panasonic Corporation, Japan)
Ultra-wideband (UWB) radar imaging has attracted attention for use in security and intelligent transportation system (ITS) applications. Conventional UWB Doppler interferometry is an effective way to obtain high-resolution images while using a simple radar system. However, this method produces ghost images when multiple closely-spaced human targets are present. To resolve this problem, we propose a new technique that combines UWB Doppler interferometry with an adaptive beamforming method called estimation of signal parameters via rotational invariance techniques (ESPRIT). We also propose a tracking and separation algorithm that uses the k-nearest neighbor method. Through a combination of numerical simulations and measurements, we demonstrate the remarkable performance improvement that can be achieved using our proposed method. The proposed method can separate multiple humans with a root-mean-square error of 5.2 cm, which makes its accuracy 1.9 times higher than that of the conventional method.
17:50 A Semicircle Bow-Tie Antenna for Subsurface Radar Applications in Civil Engineering
Valeri Mikhnev (Institute of Applied Physics, National Academy of Sciences, Belarus); Vitaly Badeev (Institute of Applied Physics, Belarus)
A modified bow-tie antenna consisting of two semicircle flares fed by a tapered microstrip line is described. Such design allows avoiding separate impedance transformers and baluns that are often poorly matched over the wide frequency band of operation resulting in considerable late-time ringing. The tapered microstrip line using one of the antenna flares as ground plane is used to transform 50 Ohm impedance of the feeding cable to the antenna impedance of around 100 Ohm. The antenna performance was tested experimentally using a concrete member made of heavy density concrete with a metal rod inserted near its center. For the sake of comparison, two other antennas designed for the same frequency band, namely tapered-slot Vivaldi antenna and conventional bow-tie antenna with impedance transformer have been tested in the same scenario.
18:10 Advanced Design of a Polarimetric X-band Antenna for Avionic Weather Radar
Giovannni Galgani and Gabriele Scozza (IDS, Italy); Roland Bolt (TNO Defense Safety and Security); Nadia Haider (TNO Defense Safety and Security, The Netherlands); Stefania Monni (TNO Defense Safety and Security); Francois Delbary (Rockwell Collins, France)
In this work we present the first phase results in the design of a fixed beam dual-polarized antenna at X-band for a polarimetric weather radar to be mounted on aircraft. Such a radar is not yet existent. Requirements pertinent to the application are presented and the different antenna system components described together with their simulated performances. Further steps in the development are anticipated.

#### L_A04 Wireless Power Transmission and Harvesting I

Localization & Connected Objects / Regular Session / Antennas
Oral Sessions: Room 352B
Chairs: Davor Bonefačić (University of Zagreb, Faculty of Electrical Engineering and Computing, Croatia), Adam Narbudowicz (Dublin Institute of Technology, Ireland)
16:30 Slot Antenna Design for a Wirelessly Powered Implantable Microcooler for Neuronal Applications
Hugo Dinis (University of Minho, Portugal); José Fernandes (DEI- University of Minho, Portugal); Paulo Mendes (University of Minho, Portugal)
Implantable medical devices are becoming smaller by the day, with more efficient electronics and smaller power demands. Nevertheless, there are some applications in which power demands are inherently high, and solutions must be found to keep the devices as small as possible. In this paper, we propose an antenna to be used in wirelessly powering a focal brain cooling implant based on a Peltier device. This antenna is designed in order to act as a heatsink for the device with the goal of minimizing its final volume, therefore design constrains such as size limitations and geometry restrictions are considered.
16:50 Feasibility of Electromagnetic Energy Harvesting Using Wearable Textile Antennas
Branimir Ivšić (University of Zagreb, Faculty of Electrical Engineering and Computing, Croatia); Mateja Babić (University of Zagreb, FER, Croatia); Andrej Galoić and Davor Bonefačić (University of Zagreb, Faculty of Electrical Engineering and Computing, Croatia)
In this paper the quantity of available environmental electromagnetic energy in typical urban scenario is investigated. Measurements of the EM power density were performed at several indoor and outdoor locations. The findings are applied to estimate the available power on typical wearable textile antenna.
17:10 Fully Inkjet Printed Wide Band Cantor Fractal Antenna for RF Energy Harvesting Application
Azamat Bakytbekov and Armando Rodriguez Maza (King Abdullah University of Science and Technology, Saudi Arabia); Mahmoud Nafe (King Abdullah University for Science and Technology, Saudi Arabia); Atif Shamim (King Abdullah University of Science and Technology, Saudi Arabia)
Energy harvesting from ambient RF signals is feasible, particularly from the GSM bands such as 900MHz,1800MHz and the 3G band at 2.1GHz. This requires a wideband receive antenna which can cover all these bands with decent gain performance and an omnidirectional radiation pattern. In this work, a novel Cantor fractal antenna has been designed which fulfills the above mentioned performance requirements. Antenna has been realized through a combination of 3D inkjet printing of plastic substrate and 2D inkjet printing of metallic nanoparticles based ink. The stable impedance and radiation performance of the antenna over a bandwidth of 0.8GHz to 2.2GHz (93 %) shows the feasibility of its employment in wide band energy harvesting applications.
17:30 Analysis of Reactance Compensation for Eliminating Cross-Coupling in Multiple-Receiver Inductive Power Transfer
Quang-Thang Duong and Minoru Okada (Nara Institute of Science and Technology, Japan)
This paper investigates reactance compensation method to eliminate the impact of cross-coupling in single frequency inductive power transfer (IPT) system with arbitrary number of receivers. Receiver-side resonance loses its optimality in multiple receiver scenarios under the existence of significant cross-coupling among receivers. Therefore, the resonant capacitances are added with compensatory reactances, whose values are analytically optimized for maximizing efficiency based on N-port network model. Cross-coupling eliminating effect of our method is verified by numerical analysis. The results also indicates that as the coupling between the transmitter and the receivers becomes weaker, the impact of cross-coupling becomes more severe, and because of that the reactance compensation becomes more effective.
17:50 Oval Double Spiral Coil for High Efficiency Wireless Power Transmission
Hisao Iwasaki and Shun Hasegawa (Shibaura Institute of Technology, Japan)
We propose the oval double spiral coil for high efficiency wireless power transmission. The high efficient wireless power transmission method is minor axis angle rotation of the receiving oval double spiral coil and offset the receiving oval double spiral coil relative to the transmitting oval coil. The simulated and measured power transmission efficiency results are agreed very well.
18:10 Simulation Framework for Performance Evaluation of Passive RFID Tag-To-Tag Communications
Lin Zhou, Florin Hutu and Guillaume Villemaud (Univ. Lyon, INSA Lyon, Inria, CITI, F-69621 Villeurbanne, France); Yvan Duroc (Univ. Lyon, UCBL, Ampere Laboratory, F-69622 Villeurbanne, France)
The concept of passive RFID tag-to-tag communications has been recently introduced and opens new promising perspectives, especially in the field of Internet-of-Things. In this paper, a simulation framework is proposed as a new tool allowing the performance evaluation of tag-to-tag radio links. The modeling takes into consideration the external source supplying the communication between tags, radiating characteristics of tag antennas, and reception system aspects. Performance results are expressed in terms of Bit Error Rate (BER) with respect to the distance between the tags and the position of the energy source relative to the position of the two tags.

#### MT_A02 Computation Techniques

Methods & Tools / Regular Session / Antennas
Oral Sessions: Room 353
Chairs: Ovidio Mario Bucci (University of Naples, Italy), Atef Elsherbeni (Colorado School of Mines, USA)
16:30 Coupling Yee Grid to Lebedev Grid in Two-Dimensions
Mahbod Salmasi and Mike Potter (University of Calgary, Canada); Michal Okoniewski (University of Calgary & Acceleware Ltd, Canada)
The standard Yee grid, though simple and robust, is not well suited to modelling anisotropic media. In contrast, the Lebedev grid is well suited, but is computationally more expensive. A methodology is presented to use classical Yee grid in isotropic regions and take advantage of Lebedev method as a subgridded region for anisotropic materials only. Two methods to couple the two regions are proposed and described in detail. The proposed methods show low reflection in a scenario where a normally incident planewave hits Yee-Lebedev interface. Also, the two techniques are shown to be both accurate and stable.
16:50 Analysis of Scattering from Electrically Large Objects Using Fast Far Field Iterative Physical Optics
Paolo De Vita, Alessandro Mori, Luca Pandolfo, Mirko Bercigli and Mauro Bandinelli (IDS Ingegneria Dei Sistemi S. p. A, Italy); Giorgio Carluccio (Delft University of Technology, The Netherlands); Matteo Albani (University of Siena, Italy)
In this paper, a fast iterative physical optics (FIPO) algorithm is proposed for analysis of scattering from electrically large objects involving multiple reflections. When the scenario to be analyzed is electrically very large, a Fast Far Field Approximation (FaFFA) algorithm, based on a domain decomposition of the scatterer surface, can be conveniently used to greatly speed-up the calculation of the induced currents at each step of the iterative procedure. In this work, an efficient and accurate interpolation scheme has been combined to the standard FaFFA algorithm implementation further reducing the complexity of the computation.
17:10 A Stable Marching-on-in-Time Algorithm Capable of Handling Multiple Excitations - Application to Wire Junction Problems
Sadasiva Rao (Naval Research Laboratory, USA)
In this work, a stable marching-on-in-time method is presented to obtain scattering response from arbitrary wire structures illuminated by a Gaussian plane wave directly in the time domain. Contrary to all the available time domain algorithms till now, the present procedure is also capable of handling multiple excitations in a trivial manner. The new procedure is based on the conventional method of moments and utilizes standard pulse functions for expansion of space and time variables. The testing procedure is accomplished by collocation procedure. The numerical results obtained using the new procedure are validated by comparing with data obtained from frequency domain solution and performing inverse discrete Fourier transform.
17:30 Non-uniform Surface Impedance Absorbing Boundary Condition for FDTD Method
Yunlong Mao (Harbin Engineering University, P.R. China); Atef Elsherbeni (Colorado School of Mines, USA); Si Li and Tao Jiang (Harbin Engineering University, P.R. China)
Surface impedance absorbing boundary (SIABC) has a comparable absorbing performance compared to CPML, but requires a sufficient long distance between the boundary and the scatter. In this paper, we focus on this issue and introduce the non-uniform SIABC. Non-uniform SIABC archives a similar absorbing performance as the uniform SIABC at a same distance, while the number of the air buffer cells is much smaller. Therefore, it is possible for us to make it more efficient relative to uniform SIABC or CPML. An example of a patch antenna is discussed to explore the accuracy and efficiency of non-uniform SIABC. We also compare the memory usage for uniform SIABC, non-uniform SIABC, and 10-layers CPML. All the results indicate that non-uniform SIABC requires much less memory, needs much less time for simulations, which makes it a potential of being one of the most popular ABCs in FDTD method.
17:50 Closed-form Evaluation of the Singular Terms in Electric Field Integral Equations
Denis Tihon (Université Catholique de Louvain & ICTEAM Institute, Belgium); Christophe Craeye (Université Catholique de Louvain, Belgium)
Using Surface Integral Equations, such as the Method of Moments (MoM), the integral of singular or nearly-singular functions over pairs of Basis function (BF) and Testing function (TF) must be evaluated. In particular, the Electric Field Integral Equation (EFIE) requires the integration of the Green's function, which asymptotically behaves as 1/R for source and observation points that are getting closer. In this paper, we provide a closed-form expression of the integral of the 1/R function for triangular BF and TF. The method presented has been made as general as possible, in order to be easily adapted to different geometries.
18:10 A Novel FDTD Formulation to Model Dispersive Chiral Media
Reza Mohammadi-Baghaee (School of ECE, University of Tehran, Tehran, Iran., Iran); Mojtaba Dehmollaian (University of Tehran, Iran); Jalil A. Rashed-Mohassel (School of Electrical and Computer Engineerimg College of Engineering & University of Tehran, Iran)
Wave propagation in a general dispersive chiral media is examined by a direct finite difference time domain (FDTD) technique. Using convolutional integrals directly in time domain without use of transformation techniques such as Z-and Mobius transformations, wave field decomposition is the main idea to drive the FDTD formulation. Time domain permittivity, permeability, and chirality of dispersive materials are found from their frequency domain expressions. These time domain models are used in convolutional terms to model wave propagation in dispersive chiral media. The co- and cross-polarized reflected and transmitted waves from a chiral slab illuminated by a normally incident plane wave are investigated. The results have a good agreement with previous ones using Z-transformation technique.

#### CS22 Innovative Antennas for TT&C and PDTM Satellite Links

Space / Convened Session / Antennas
Oral Sessions: Room 362/363
Chairs: Anthony Bellion (CNES, France), Goutam Chattopadhyay (JPL, USA)
16:30 RUAG Space Activities in the TT&C, GNSS and Data-Downlink Antenna Field
Jan Zackrisson (RUAG Space AB, Sweden)
This paper presents some of our antenna activities in the TT&C, GNSS and Data-Downlink area. Our involvement in such antenna designs spans over a 40 year period starting in the mid 70ies, first within the antenna group at LM Ericsson and Saab Ericsson, and now at RUAG
16:50 New Mechanical Steering Compact Antenna Solutions in X and Ka Band for Payload Telemetry
Jerome Lorenzo, Benjamin Monteillet and Nicolas Ferrando (Thales Alenia Space, France); Jerome Brossier (Thales, France); Patrick Leconte (Thales Alenia Space, France)
This paper presents new mechanical steering compact antenna solutions under development in Thales Alenia Space (TAS) for X and Ka Band applications dedicated to Payload Telemetry requiring high data rate and wide scan steerable domain. The proposed innovative solutions are based on high performances RF feed assembly including rotary joint. The feed assembly is embedded in a very compact dual reflector geometry which allows to minimize the antenna overall volume including kinematic. The proposed design includes common building blocks between X and Ka band Telemetry applications. The TAS antenna patented design proposed is very competitive and can be also used for Telecoms constellations and Inter Satellite Link applications.
17:10 TT&C and Payload Telemetry Antennas for Nanosatellite - Eye-Sat Nanosatellite Program
This paper presents a compact single-feed circularly polarized S-band antenna and a medium gain X-band antenna for Nanosatellite TT&C applications. The S-Band antenna is composed of two crossed dipoles printed on both sides of a substrate, center-fed by a 50Ω coaxial cable. The bandwidth of the antenna is 17% (1.98 - 2.35 GHz) and covers TeleCommand and TeleMetry band. The size of the entire structure including the radome and the satellite interface is 0.58λmin of diameter and 0.081λmin of height where λmin is the wavelength at the lowest frequency. The X-band medium gain antenna is composed of 4 single feed circularly polarized patches fed by a sequential phase rotation network that provides an axial ratio better than 1dB. The bandwidth of the antenna is 11% (7.7 - 8.6GHz) and the gain is better than 12dB in the entire payload telemetry band. The final structure is included in 72.5x72.5x9mm3.
17:30 Multimode Reconfigurable Nanosatellite Antenna for PDTM Application
Ali Siblini (Limoges University, France); Bernard Jecko and Eric Arnaud (XLIM, France)
This paper deals with the design of a new reconfigurable beam antenna used to improve the efficiency of spatial telemetry links on nanosatellite. This agile beam antenna is not built on the well-known array concept: AESA (Agile Electronically Scanned Array) but using a new one called ARMA (Agile Matrix Radiating Antenna) ; Marpem in French
17:50 CubeSat Deployable Ka-band Mesh Reflector Antenna Development for Earth Science Missions
Nacer Chahat (NASA-JPL, Caltech, USA); Jonathan Sauder (NASA-JPL / Caltech, USA); Mark Thomson (NASA-JPL / Caltech, France); Yahya Rahmat-Samii (University of California, Los Angeles (UCLA), USA); Richard Hodges (NASA-JPL / Caltech, USA)
CubeSats are positioned to play a key role in Earth Science, wherein multiple copies of the same RADAR instrument are launched in desirable formations, allowing for the measurement of atmospheric processes over a short, evolutionary timescale. To achieve this goal, such CubeSats require a high gain antenna that fits in a highly constrained volume. This paper presents a novel mesh deployable Ka-band antenna design that folds in a 1.5U (10×10×15cm3) stowage volume suitable for 6U (10×20×30cm3) class CubeSats. Considering all aspects of the deployable mesh reflector antenna including the feed, detailed simulations and measurements show that 42.6 dBi gain and 52% aperture efficiency is achievable at 35.75GHz. The mechanical deployment mechanism and associated challenges are also described, as they are critical components of a deployable CubeSat antenna. Both solid and mesh prototype antennas have been developed and measurement results show excellent agreement with simulations.
18:10 Telemetry X-band Antenna Payload for Nano-satellites
Rodrigo Manrique (MVG Industries, France); Gwenn Le Fur (CNES, France); Nicolas Adnet (MVG Industries, France); Luc Duchesne (SATIMO, France); Jean-Marc Baracco (Mardel, France); Kevin Elis (CNES, France)
This paper presents a compact X-band antenna with an isoflux radiation pattern and circular polarization. It consists of a miniaturized helix antenna connected to a stripline circuit that provides a sequential rotation feeding. The antenna is arranged over a vertically corrugated ground plane and it has been optimized for a CubeSat 3U nano-satellite platform. Its design, manufacture and results are here presented.

#### WG_01 Propagation

WG Meetings & Workshops: Room 313/314
Chair: Thomas Kürner (Technische Universität Braunschweig, Germany)

## Tuesday, March 21

### Tuesday, March 21, 08:40 - 12:30

#### CS02 Additive Manufacturing for Antenna and RF Components

Space / Convened Session / Antennas
Room: Oral Sessions: Auditorium Havane
Chairs: María García-Vigueras (IETR-INSA Rennes, France), Ronan Sauleau (University of Rennes 1, France)
08:40 ESA's Recent Developments in the Field of 3D-Printed RF/Microwave Hardware
Additive Manufacturing (AM) is considered a strategic technology for space applications specifically enabling breakthrough developments of RF hardware. The implementation of AM will allow RF hardware manufacturers to enhance significantly the performance of their products. The assessment of different AM approaches has already started and will consider the whole process chain, including design, material supply, processing, post processing, qualification and verification, and standardization. This paper will present the past and current developments in the field of 3D printing for RF/Microwave hardware. Future activities will also be presented.
09:00 Using Additive Manufacturing for Feed Chain and Other Passive Microwave Components
Paul Booth (Airbus Defence and Space Ltd., United Kingdom (Great Britain)); Richard Roberts (Airbus Defence and Space Ltd, United Kingdom (Great Britain)); Michael Kilian (Airbus Defence and Space GmbH, Germany); Christian Hartwanger (Airbus, Germany)
This paper describes the use of additive manufacturing to realise satellite feed chain and other waveguide components. The advantages and drawbacks of different processes are discussed and examples of components and their performance are presented. A number of the presented components exploit the inherent geometric freedom of additive manufacturing. The near term outlook and ongoing development activities of additive manufacturing at Airbus Defence and Space conclude the paper.
09:20 Manufacturing of Waveguide Components for SatCom Through Selective Laser Melting
Oscar A. Peverini (Istituto di Elettr. e di Ingegneria dell'Inform. e delle Telecom. ( IEIIT- CNR ), Italy); Mauro Lumia (CNR, Italy); Flaviana Calignano and Diego Manfredi (IIT, Italy); Giuseppe Addamo (Istituto di Elettr. e di Ingegneria dell'Inform. e delle Telecom. (IEIIT-CNR), Italy); Massimo Lorusso and Elisa Ambrosio (IIT, Italy); Giuseppe Virone (Consiglio Nazionale delle Ricerche, Italy); Paolo Fino (IIT, Italy); Riccardo Tascone (Istituto di Elettr. e di Ingegneria dell'Inform. e delle Telecom. (IEIIT- CNR), Italy)
This paper presents the developments at CNR-IEIIT and IIT concerning microwave waveguide components manufactured through selective laser melting (SLM). The latter is an additive manufacturing process based on the selective melting of a metal powder bed through a laser. Application of this technology to the development of antenna-feed chains aimed at satellite communication (SatCom) is discussed. Description of the process and experimental activities for the assessment of the electromagnetic properties of parts are reported. Measured performance of Ku/K-band filters and Ku-band feed-horns manufactured through SLM will be presented. The results achieved prove that SLM can be a valuable technology both to develop novel components and to increase system integration.
09:40 A Study of the Additive Manufacturing Technology for RF/Microwave Components
Adrian Gomez (Public University of Navarra, Spain); Fernando Teberio (Public University of Navarre, Spain); Aitor Martinez (ANTERAL, Spain); Jon Percaz (Public University of Navarra, Spain); Israel Arnedo (Public University of Navarre, Spain); Itziar Maestrojuán (Anteral, Spain); Ivan Arregui (Public University of Navarre, Spain); Gonzalo Crespo (Anteral, Spain); Txema Lopetegi and Miguel Laso (Public University of Navarre, Spain); Jorge Teniente (Public University of Navarra & Institute of Smart Cities, Spain)
In this work an overview of the different Additive Manufacturing techniques will be presented. Each technique will be compared in terms of dimensional accuracy, surface roughness, and quality taking into account the most suitable applications for each one. Then, two applications will be studied: (a) fast prototyping of waveguide component designs using profesional grade 3D printers for electromagnetic validation purposes, and (b) 3D printing of waveguide hardware products as a production technology using production grade 3D printers. The first application will be studied with a research center approach, where many different designs are manufactured in order to validate a design technique or a model. The second application will be studied a with a company approach, where the best quality at a lower price is pursued.
10:00 Electrical Tests of Ka Band Input Filters for Space Applications
Monica Martinez Mendoza, Santiago Sobrino and Ana Isabel Daganzo (Thales Alenia Space, Spain); Tomislav Debogovic, Mirko Favre and Emile de Rijk (SWISSto12 SA, Switzerland)
In this paper, the fabrication of Ka band input filters by means of additive manufacturing technology is tested for space applications. Measurements of manufactured prototypes against recurrent filters designed with specifications used in real satellite communication systems are performed, and conclusions about the potential of the additive manufacturing technology for space applications are stated.
10:20 Coffee Break
10:50 3D-Printed Quasi-Optical Antenna-Systems for Mm-wave Communications
Aimeric Bisognin (University Nice Sophia-Antipolis & STMicroelectronics, France); Diane Titz (University Nice Sophia Antipolis, France); Cyril Luxey (University Nice Sophia-Antipolis, France); Frédéric Gianesello (STMicroelectronics, France); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal); Daniel Gloria (STMicroelectronics, France); Carlos Del-Río (Universidad Publica de Navarra & Institute of Smart Cities, Spain)
The rapid growth of wireless data drives the development of new technologies. We have here in mind the current works on 5G standardization, wireless backhaul developments in V/E Band as well as low orbit mobile satellite service development in Ku band. For all those communication systems, the availability of high performance and cost effective antenna is key. To address this need, fundamental enablers lie in manufacturing technologies able to handle complex 3D shape while providing at the same time fast and low cost prototyping as well as the ability to support volume production. This paper illustrates how 3D printing and digital manufacturing technologies might help to develop innovative and cost effective antenna solutions in order to address new business challenges. Index Terms — 3D printing, digital manufacturing, antenna, millimeter waves, 5G, Ku band, low orbit satellite, backhaul.
11:10 3D-printed Ka-band Waveguide Array Antenna for Mobile SATCOM Applications
Frédéric Bongard, Martin Gimersky, Stephen Doherty, Xavier Aubry and Mikael Krummen (Viasat Antenna Systems SA, Switzerland)
Purely passive, mechanically steered waveguide-fed horn arrays are good candidates to satisfy the current need for low-to-medium-profile antennas for mobile user terminals for SATCOM applications. In this work, a unique waveguide feed architecture is proposed, which enables the realization of grating lobe-free, wideband, low-profile waveguide-fed horn arrays operating with dual circular polarization. The realization of such structures using 3D printing is investigated, showing the promise of such techniques in terms of design flexibility. To demonstrate the potential of the proposed waveguide array architecture combined with 3D printing, an 8-by-8 antenna array operating in the 20 GHz SATCOM Ka band has been developed and is presented. This antenna exhibits an aperture efficiency of about 80% over a relative bandwidth larger than 10%.
11:30 Polymer-Based Metal Coated Additive Manufactured V- And W-band Antenna Feed Chain Components
Esteban Menargues (Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland); Mirko Favre and Alexandros I. Dimitriadis (SWISSto12 SA, Switzerland); Santiago Capdevila (EPFL & École Polytechnique Fédérale de Lausanne, Switzerland); Tomislav Debogovic (SWISSto12 SA, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland); Maarten van der Vorst (European Space Agency, The Netherlands); Emile de Rijk (SWISSto12 SA, Switzerland)
In this paper an additive manufactured (AM) W-band monolithic feed chain is presented. The feed chain, which consists of a corrugated horn antenna and a turnstile orthomode transducer (OMT), operates over the entire W-band (75 − 110 GHz) and fulfills typical EM specifications for space applications (RL > 20 dB, IL < 1 dB and Xpol < −30 dB). Both the OMT and the horn have been designed by exploiting the design freedom offered by AM, but also taking into account its specific technological constraints. The presented W-band design can be straightforwardly scaled to V-band.
11:50 3D-printed Ka-band Antenna Based on Stereolithography
Joana Silva (Huber+Suhner, Switzerland); María García-Vigueras (IETR-INSA Rennes, France); Tomislav Debogovic (SWISSto12 SA, Switzerland); Juan R Mosig (Ecole Polytechnique Federale de Lausanne, Switzerland)
This paper presents a circularly-polarized dual-band antenna for Ka-band satellite communications which operates simultaneously in both civil and military downlink (17.7-21.2 GHz) and uplink (27.5-31 GHz) bands. The antenna is composed of a metallic ridged cavity that is perforated with a crossed-slot. This cavity is excited in sequential rotation through four feeding coaxial cables, thus producing circular polarization (CP). The required feed distribution is obtained by a dedicated beam-forming network (BFN) able to provide phases to generate right/left-handed CP in the downlink/uplink-bands, respectively. The prototype of the antenna cavity is 3D printed basing on stereolithography (SLA), while the BFN is realized in printed circuit technology. Good agreement is obtained between theoretical and measured results, thereby validating the antenna concept and confirming the strong potential of SLA to conceive compact RF components.
12:10 Innovative Materials and Fabrication Process to Develop New RF Components and Concepts
Cyrille Menudier (XLIM - UMR CNRS 7252 - University of Limoges & Antennas & Signals, France); Marc Thevenot (XLIM-UMR CNRS 7252, University of Limoges, France); Laure Huitema (Xlim Laboratory, France); Eric Arnaud (XLIM, France); Thierry Monediere (XLIM-UMR 6172-CNRS, University of Limoges, France); Olivier Tantot (XLIM - University of Limoges, France); Stéphane Bila (XLIM UMR 7252 Université de Limoges/CNRS, France); Nicolas Delhote (XLIM - UMR CNRS, University of Limoges, France)
Recent developments on materials for additive manufacturing and associated fabrication process offer new opportunities for the design of antennas and RF components. In this paper, different technologies used by our laboratory are presented and their application to different types of antennas and microwave components, especially filters, is shown. A brief overview of the advantages of such technologies for joint-design and original architectures is also presented.

### Tuesday, March 21, 08:40 - 10:20

#### W_A01 Adaptive & Reconfigurable Antennas for Wireless Networks

Wireless Networks / Regular Session / Antennas
Oral Sessions: Room 341
Chairs: Stefan Lindenmeier (Universität der Bundeswehr, Germany), Ville Viikari (Aalto University & School of Electrical Engineering, Finland)
08:40 Switched Beam Patch Array Antenna Using SPDT GaN HEMT Switches
Abdelaziz Hamdoun (University of Rennes 1, France & IETR, Canada); Mohamed Himdi (Université de Rennes 1, France); Olivier Lafond (IETR, France); Langis Roy (Carleton University, Canada)
In this paper, a single-fed four-panel 4x1 patch array antenna operating at 2.43 GHz with switched beam capability is proposed. The design allows the beam to be switched between four discrete directions giving 360° coverage. The antenna beam is switched over the azimuth plane for Φ = 0°, Φ = 90°, Φ = 180°, and Φ = 270°. The beam control is achieved by using GaN-based HEMT SPDT switches. Only three SPDT switches are integrated directly into the structure, allowing its nature to be electrically controlled over the desired four directions. Simulated and measured reflection coefficients and radiation patterns for the four cases are presented and discussed, showing good agreement. The antenna gain is around 3.8 dB including switches losses at 2.43 GHz.
09:00 A Wideband Automotive Antenna for Actual and Future Mobile Communication 5G/LTE/WLAN with Low Profile
Sertan Hastürkoglu (University of the Bundeswehr Munich, Germany); Stefan Lindenmeier (Universität der Bundeswehr, Germany)
For integration into flat mounting volumes in cars a new wideband antenna is presented covering all frequency bands for cell phone LTE and 5G starting with the LTE low band at 698 MHz up to the WLAN frequency bands at 6 GHz. The performance of the antenna is shown by way of measurement and simulation as a single part and via measurement of an antenna pair in a car on a turntable regarding mutual coupling and influences of the mounting environment. It can be shown that for all the considered frequency bands the gain of the wideband antenna is deviating by only around 2.5 dB from the gain of a set of monopole antennas which are ideally matched for the different frequency bands.
09:20 Technique to Increase Directivity of a Reconfigurable Array Antenna for Wireless Sensor Network
Akimu Dihissou (Université Côte d'Azur & LEAT, France); Aliou Diallo (Universite Cote d'Azur, France); Philippe Le Thuc (Université Côte d'Azur, CNRS, LEAT, France); Robert Staraj (Universite Cote d'Azur, CNRS, LEAT, France)
In this paper, a technique to maximize the directivity of an antenna array is presented. It consists of a fed monopole and a loaded parasitic one. The nature and value of the load are obtained using the Uzkov equations that calculate the current weighting coefficients in the case of two separately fed antennas to maximize the gain and the directivity in one direction. Reconfigurability is achieved by using reflectors and directors activated by pin diodes to reduce the back radiation and pointing in the desired direction. Thus a system of two elements, one fed and the other loaded with an inductor, having a maximum gain of 5.2 dBi at 2.45GHz in azimuthal directions 90° and 270° is obtained. The system is compared with a system of two antennas fed separately.
09:40 Wideband U-Slot Patch Antenna with Reconfigurable Radiation Pattern
Jie Wang, Jiexi Yin, Haiming Wang, Chen Yu and Wei Hong (Southeast University, P.R. China)
A wideband U-slot patch antenna with reconfigurable radiation pattern is investigated. The antenna composes three patches which are one coaxial-fed U-slot driven patch and two parasitic patches located near the two non-radiating edges of the middle driven patch. One varactor diode is installed in middle of each parasitic patch. Both beamwidth and main lobe direction can be tuned by controlling the direct current bias voltages of the two varactor diodes. The presented antenna has wide operating bandwidth of 6.4% at 1.4 GHz. Its beamwidth can be continuously changed from 60 degree to 130 degree and its main lobe direction can scan from -20 degree to +20 degree in the H-plane. Its peak antenna gain is 8.8 dBi with gain variation of 3.5 dB along the entire beamwidth tuning range and 8.5 dBi with gain variation of 2.5 dB along the entire beam scanning range. Simulation and measurement results agree well.
10:00 Further Investigations on the Behavior of a Frequency Reconfigurable Antenna Cluster
Jari-Matti Hannula and Jari Holopainen (Aalto University School of Electrical Engineering, Finland); Ville Viikari (Aalto University & School of Electrical Engineering, Finland)
A recently published paper presented a novel concept for obtaining frequency reconfigurable behavior by combining multiple antenna elements and weighting the feed signals for each element. In this paper, we clarify some concepts presented in that paper and analyze the antenna structure in more detail.

### Tuesday, March 21, 08:40 - 12:30

#### C_M01 MIMO measurements

Cellular Communications / Regular Session / Measurements
Oral Sessions: Room 342A
Chairs: Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France), Michael Jensen (Brigham Young University, USA)
08:40 Cavity Modes Inside a Mode-Stirred Reverberation Chamber Extracted Using the Matrix Pencil Method
Francois Sarrazin (University of Paris-Est-Marne-la-Vallée & ESYCOM, France); Elodie Richalot (Université Paris-Est (Marne-la-Vallée), France)
This paper presents the extraction of the modes resonating inside a mode-stirred reverberation chamber using the Matrix Pencil method. An increasing time-window technique is investigated as a process to discriminate the true modes and the spurious ones that appear due to the measurement noise.
09:00 Over-the-Air Testing of LTE-Advanced Features Using Reverberation Chamber
The 4G standard is constantly evolving with more features being added to the standard specifications. Carrier aggregation and higher order MIMO are examples of features used to support higher data rates. The addition of features puts new requirements on wireless devices and this increasing complexity implies that Over-the-Air testing is more important than ever. At the same time it is important to keep the complexity of test setups to a minimum and to reduce measurement time, given the constant addition of new test cases. This paper elaborates on the RC as a fast, accurate and comprehensive Over-the-Air testing environment for assessing advanced features of state-of-the-art wireless devices. It is shown that a number of different testing scenarios can be realized with one test chamber using time efficient measurement algorithms. This test chamber can also be used for legacy standards and for assessing traditional metrics for antenna and wireless device performance.
09:20 Base Station Over-the-Air Testing in Reverberation Chamber
Christian Lötbäck and Klas Arvidsson (Bluetest AB, Sweden); Mats Högberg and Mattias Gustafsson (Huawei Technologies Sweden AB, Sweden)
This paper elaborates on the feasibility of the reverberation chamber for base station Over-the-Air testing. Several key parameters are measured and compared to results from conducted testing, showing that the metrics currently measured in conducted mode can be translated to Over-the-Air metrics with high accuracy. In addition, an analysis of major uncertainty contributions is provided. This analysis shows that there is insignificant impact on the measurement accuracy when measuring antennas with high gain in the reverberation chamber.
09:40 Gradient Ascent Based Optimization for a Reconfigurable OTA Chamber
Matthew Arnold (Brigham Young University, USA); Rashid Mehmood (Wavetronix LLC, USA); Michael Jensen (Brigham Young University, USA); Jon Wallace (Lafayette College, USA)
A reconfigurable over-the-air chamber represents a reverberation chamber whose walls are lined with antennas that are terminated in reconfigurable impedances, allowing synthesis of a wide range of channel conditions for over-the-air testing of mobile wireless devices. While these chambers have potential for practical device testing, finding the right impedances to achieve the desired channel characteristics remains a challenging problem. This work explores the use of a simple gradient ascent optimization algorithm to determine the impedance states that achieve a specified spatial structure in the multipath, as characterized by the multipath power angular spectrum. The results highlight that the optimization is effective for synthesizing a desired power angular spectrum with a directive peak and a relatively low sidelobe level.
10:00 Semi-Omnidirectional Dual-Polarized Wideband Multiport Antennas for MIMO Applications in Random-LOS and RIMP
Sadegh Mansouri Moghaddam, Andrés Alayon Glazunov and Jian Yang (Chalmers University of Technology, Sweden); Mattias Gustafsson (Huawei Technologies Sweden AB, Sweden)
We present two configurations of multiport antennas for Multiple-input Multiple-output (MIMO) application. The configurations are comprised of three and four dual-polarized selfgrounded bowtie antenna as the element, respectively. The MIMO performance of both antennas is evaluated in Random Line-of-Sight (Random-LOS) and Rich Isotropic Multipath (RIMP) channel models as two edge propagation environments. Both configurations provide 360 azimuth and 120 elevation angular coverage in Random-LOS and full sphere coverage in RIMP. Using digital threshold receiver model and Zero-Forcing receiver, the performances of both configurations are evaluated in terms of Probility of Detection (PoD) and MIMO multiplexing efficiency calculated at 95% PoD level. The simulated results show a good performance for both structures in two edge environments, which can be concluded as a good performance in a real life situation.
10:20 Coffee Break
10:50 A 3-D Wide- Band Setup for Over-The-Air Test in Anechoic Chamber
Mounia Belhabib and Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France); Bernard Uguen (University of Rennes I, France)
In this paper we present a 3D wide-band measurement bench for Over-the-Air (OTA) tests. The setup is composed by twelve double-polarized antennas, placed around the Zone Under Test (ZUT), on three different elevation planes. A characterization of the ZUT was performed in order to assess the differences, in terms of amplitude and phase of the incident field, according to the frequency considered.
11:10 MIMO Antenna Performance Assessment Based on Open Source Software Defined Radio
Cyril Buey (Orange Labs); Theoni Magounaki (Orange Labs, France); Fabien Ferrero (University Nice Sophia Antipolis, CNRS, LEAT & CREMANT, France); Philippe Ratajczak (Orange Labs, France); Leonardo Lizzi (Université Côte d'Azur, CNRS, LEAT, France); Florian Kaltenberger (Eurecom, France)
This paper presents a low-cost measurement method for MIMO antenna performance assessment based on the open-source initiative OpenAirInterface. A first measurement is presented with a prototype with 8 antennas at 2.5GHz integrated into a 140*140x40mm femto cell and using Laser Direct Structuring (LDS) technique. The setup is validated trough a beamforming gain measurement in a MISO 4x1 configuration in LTE TDD mode.
11:30 The Variation of Clusters with Increasing Number of Antennas by Virtual Measurement
Chao Wang and Jianhua Zhang (Beijing University of Posts and Telecommunications, P.R. China); Lei Tian (Beijing University of Posts and Telecommunications & Wireless Technology Innovation Institute, P.R. China); Mengmeng Liu (Beijing University of Posts and Telecommunications, P.R. China); Ye Wu (Huawei Technologies, P.R. China)
This paper shows the variation of clusters with the increasing number of antennas. The data was collected from the massive MIMO mobile measurement at 3.5 GHz, in line of sight (LoS) and non line of sight (NLoS) conditions, respectively. And the virtual measurement method is used to form the 64-element, 128-element and 256-element virtual antenna array from the 32-element antenna array. After estimating parameters by the space-alternating generalized expectation maximization (SAGE) algorithm and clustering by KPowerMeans algorithm, the parameters of clusters are displayed in angular domain and delay domain. The cluster-level angular power spectrums (APS) are shown, the intra-cluster angular spread (AS) and intra-cluster delay spread (DS) of these 4 groups of data are calculated, to display the clusters' variation when antenna number increases.
11:50 Antenna Mutual Coupling Effect on MIMO-OFDM System in the Presence of Phase Noise
Xiaoming Chen (Xi'an Jiaotong University, P.R. China); Shuai Zhang (Aalborg University, Denmark)
This work investigates the antenna mutual coupling effect on multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems with oscillator phase noises. Since the antenna correlation when taking the mutual coupling effect into account is smaller than that when the mutual coupling effect is omitted, it is shown that, at small antenna separations, the error rate performance of the MIMO-OFDM system when taking the mutual coupling effect into account can be smaller than that when the mutual coupling effect is not considered (even though the mutual coupling degrades the antenna radiation efficiencies and mismatches). It is also shown that, with sufficient subcarrier spacing, the phase noise effect can be mitigated by simple phase noise compensation regardless of the antenna correlation or mutual coupling.
12:10 5G Communications in High Speed and Metropolitan Railways
Ana Gonzalez-Plaza (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain); Juan Moreno (Universidad Politécnica de Madrid, Spain); Iñaki Val, Aitor Arriola and Pedro Rodriguez (IK4-IKERLAN, Spain); Florentino Jimenez (Universidad Politécnica de Madrid, Spain); Cesar Briso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain)
Railway transportation is increasing very fast in all countries, and as a consequence new railways demand high quality communications for control and signaling of trains, as well as high capacity communications for passengers. However, current communications systems cannot provide these services, so 5G systems will be needed to replace old GSM-R and dedicated systems for railway signaling. Also, 5G terrestrial and satellite technologies will provide high data rate services to passengers. In this paper we describe the main characteristics and requirements for critical and non-critical communications in railways. Results are useful to choose the communications technologies that can fulfill these requirements in the near future.

#### CS05 Advances in Electromagnetic Diagnostics and Biomedical Sensors

Biomedical / Convened Session / Propagation
Oral Sessions: Room 342B
Chair: Raquel C. Conceição (Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Portugal)
08:40 Loss Tangent Effect on the Accurate Design of Microwave Sensors for Blood Glucose Monitoring
Sandra Costanzo (University of Calabria, Italy)
The effect of loss tangent variation is properly faced in this work for the accurate design of microwave sensors to be applied in the non-invasive monitoring of blood glucose. Bio-antenna optimization is performed by accurately considering the complex permittivity variation of the biological radiation medium. At this purpose, preliminary dielectric data are experimentally collected by using a standard open-ended coaxial probe. Then, the above complex dispersive data are exploited to optimize the antenna dimensions. Return loss measurements on water-glucose solutions with different concentrations are reported to prove the strong enhancement in the prediction of the resonant shift due to the variation of glucose level, when properly considering the loss tangent variation. Preliminary simulation results on blood are also reported.
09:00 Dosimetric Characterizations of Electromagnetic Fields Exposures for Biomedical Applications
Delia Arnaud-Cormos, Sylvia M Bardet and Rodney O’Connor (University of Limoges, CNRS, XLIM, France); Philippe Leveque (University Limoges, CNRS, XLIM, France)
This paper illustrates advances in dosimetry techniques for the characterization of biological entities exposed to electromagnetic fields. Specific developments for the exposure of cancer cells and tumors to pulsed electric fields are introduced. Experimental and numerical technics for the investigations of pulses with durations in the nanosecond domain (nsPEF) and intensities up of a few tens of MV/m are presented.
09:20 Exposure Limits and Dielectric Contrast for Breast Cancer Tissues: Experimental Results Up to 50 GHz
At microwave and mm-wave frequencies, the interactions of the human tissue with electromagnetic fields depend on the dielectric properties of the tissue itself. The knowledge of these properties of healthy and malignant tissues, beyond to be crucial in several biomedical applications, is necessary to fix the safety thresholds in policy-making and the exposure limits for the human body. In particular, breast tissues are of particular interest due to the relatively large diffusion of breast cancer. In literature, experimental data are available up to 20 GHz, consequently at mm-wave frequencies they are only derived from extrapolations. This paper presents a feasibility study based on the experimental results of a dielectric characterization of breast tissues. Two main aspects are addressed. First, the contrast achievable between normal and tumorous tissues, a key parameter for several biomedical applications. Second, the compliance of a mm-wave imaging system for breast cancer detection with the ICNIRP recommendations.
09:40 Towards 3D Field Intensity Shaping for Biomedical Applications
Domenica A. M. Iero (Università Mediterranea di Reggio Calabria, Italy); Gennaro G. Bellizzi (Mediterranea University of Reggio Calabria & IREA - National Research Council, Italy); Tommaso Isernia (University of Reggio Calabria, Italy); Lorenzo Crocco (CNR - National Research Council of Italy, Italy)
3D field shaping is a canonical problem in wave physics that could impact next generation of therapeutic systems. In this framework, we present an innovative and effective strategy that relies on the convex relaxation of the original NP hard problem by taking inspiration from the optimal constrained power focusing method. The formulation presented in this paper in terms of convex programming allows an efficient solution of the problem at hand by means of local search algorithms.
10:00 Feasibility Assessment of a Banach-Space Inversion Procedure for Biomedical Applications
An approach for microwave imaging of hemorrhagic brain strokes is proposed in this paper. The developed procedure is based on the solution of the electromagnetic inverse-scattering problem by using a Newton-scheme developed in the framework of the Lp Banach spaces. Preliminary numerical results, aimed at evaluating the feasibility of the developed approach for brain stroke detection, are reported.
10:20 Coffee Break
10:50 Microwave Tomographic Image Improvement by Fitting to a Cole-Cole Relaxation Model
Tomas Rydholm, Andreas Fhager and Mikael Persson (Chalmers University of Technology, Sweden); Paul M Meaney (Dartmouth College, USA)
We have reconstructed microwave tomographic images of the Supelec breast phantom using our imaging fixture in combination with a multi-channel vector network analyzer. During this study we were able to recover images without the support of a priori information over a broad frequency range - 1100-1900 MHz. We then fitted the spectral values at each pixel within the field of view to a Cole-Cole curve and extracted the coefficients at each location. While the individual images at each frequency provided reasonably representations of the target permittivity and conductivity distributions, the fibroglandular features were generally quite blurred with the surrounding adipose region. However, several of the Cole-Cole coefficient plots provided a higher level of resolution for the inclusions. While there was a noticeably high level of artifacts outside of the breast phantom perimeter, the internal structures are quite representative of the target.
11:10 Radio Telemetry Performance of Liver Implanted Ultra Wideband Antenna
Pongphan Leelatien, Koichi Ito and Kazuyuki Saito (Chiba University, Japan); Akram Alomainy (Queen Mary University of London, United Kingdom (Great Britain)); Manmohan Sharma (Nanyang Technological University, Singapore); Yang Hao (Queen Mary University, United Kingdom (Great Britain))
This paper considers a liver implanted antenna and its associated radio telemetric channel using ultra wideband (UWB) technology. The performance of both the implant antenna and the radio channel is evaluated numerically and experimentally using human equivalent multilayer phantom to obtain S-parameter results within the 4-8 GHz band for various distances between the implanted antenna and a body-worn one. The results show a strong potential in using UWB range for such wireless implant communication scenarios and for the intended applications.
11:30 Composite Aircraft Lightning Strike Protection Damage Evaluation Using Microwave Microscopy Techniques
Leandro Rufail (Polytechnique Montreal, Canada); Jean-Jacques Laurin (Ecole Polytechnique de Montreal, Canada); Fidele Moupfouma (Bombardier Aerospace, Canada)
We are presenting a new application of microwave microscopy for the diagnostic of the lightning strike protection mesh used in composite aircraft skin. With this new approach it is possible to resolve defects as small as one cut strand under the paint. We also discuss its ability to measure the paint thickness.
11:50 On-Body Skin Confined Propagation for Body Area Networks (BAN)
Qiang Zhang (University of Pierre and Marie Curie UPMC, France); Julien Sarrazin (University of Pierre & Marie Curie UPMC, France); Massimiliano Casaletti (Sorbonne Universités UPMC, France); Luca Petrillo (Université Libre de Bruxelles, Belgium); Philippe De Doncker (ULB, Belgium); Aziz Benlarbi-Delaï (Sorbonne Universités, UPMC Paris 06, France)
The augmenting need for remote monitoring and treating patients by biophysical sensors interconnected via Body Area Networks (BAN) has recently called researchers' attention. The private and confidential transferred data in such application require high information security. One of the solutions is to use human body as a transmission channel. The body surface-confined transmission restricts the off-body detection, increasing the system security. Also, it reduces the interference between BAN users. For better understanding the body channel propagation mechanism, a lossy multilayered human body model, made of skin, fat, muscle tissues, is established for numeric analysis in this paper, using complex frequency dependent dielectric property for each tissue. Transverse Resonance Method is applied to calculate dispersion and attenuation in the propagation direction up to 60GHz. Since the tissue thickness varies with different localization and different person, 3 skin thicknesses, typically 0.5 mm, 1 mm, and 1.5 mm, are considered and compared.
12:10 Determination of Complex Permittivity of Arbitrarily Shaped Homogenous Materials via Waveguide Measurements
Ahmet Aydoğan (Marmara University & Istanbul Technical University, Turkey); Funda Akleman and Serkan Şimşek (Istanbul Technical University, Turkey)
In this study, complex permittivity of arbitrarily shaped homogenous materials loaded in different shaped waveguides (rectangular waveguide and circular waveguide) is determined through an iterative inverse algorithm. S-parameters are calculated for chosen material numerically via Method of Moments (MoM), in place of real measurement data for sake of testing algorithm as a first step. Inverse algorithm depends on calculating transmission-reflection coefficients (two port S-parameters) with respect to updated complex permittivity, started with an initial guess. At each step, calculated S-parameters (either S11 and/or S21) can be used to update complex permittivity in sense of Newton-Raphson numerical approach. Problem is reduced to finding the roots of iterative equation, which is a function of complex permittivity.

#### CS25 Mm- and THz- wave Propagation Measurements and Modelling for Ultra-high Data Rate Communications (COST CA15104 IRACON)

High Data-rate Transfer / Convened Session / Propagation
Oral Sessions: Room 343
Chairs: Claude Oestges (Université Catholique de Louvain, Belgium), Alenka Zajic (Georgia Institute of Technology, USA)
08:40 Design and Calibration of a Double-directional 60 GHz Channel Sounder for Multipath Component Tracking
Ruoyu Sun (National Institute of Standards and Technology, USA); Peter Papazian and Jelena Senic (NIST, USA); Yeh Lo (NTIA, USA); Jae-Kark Choi (National Institute of Standards and Technology, USA); Kate A. Remley and Camillo Gentile (NIST, USA)
The 60 GHz band is being considered for many high-bandwidth wireless applications. To support standards development for these applications, NIST has developed an untethered 60 GHz, 8×16 MIMO channel sounder. It employs a pseudorandom bit sequence with a bandwidth of 4 GHz. The sounder can precisely measure radio propagation channel characteristics such as path loss, small-scale fading, delay dispersion, absolute delay, angle-of-arrival (AoA), angle-of-departure (AoD), and Doppler power spectrum. Its ability to measure the time dynamics of the millimeter-wave radio channel, when untethered and in motion, is unique. It employs electronically-switched MIMO antenna arrays, a robot for moving measurements and an automated one-dimensional positioner for precision measurements at fixed locations. Sounder performance is improved by use of pre-distortion filters and precision calibration of the RF and timing systems. Data showing initial AoD and AoA estimation error are presented along with initial test results for ground-plane reflection.
09:00 Polarimetric Analysis of Reverberation Times for 94 GHz Indoor Communication
Brecht Hanssens (Ghent University, Belgium); Maria Teresa Martinez-Ingles (University Centre of Defence at the Spanish Air Force Academy, MDE-UPCT, Spain); Emmeric Tanghe (Ghent University, Belgium); David Plets (Ghent University - imec, Belgium); Jose-Maria Molina-Garcia-Pardo (Universidad Politécnica de Cartagena, Spain); Claude Oestges (Université Catholique de Louvain, Belgium); Luc Martens (Ghent University, Belgium); Wout Joseph (Ghent University/IMEC, Belgium)
This paper presents a measurement-based analysis of both the specular- and dense multipath components (SMC and DMC) at 94 GHz in an indoor environment. A total of 15 positions were measured with a virtual antenna array system, from which we have calculated Power Delay Profiles (PDP). A method was developed that allowed for the full-polarimetric estimation of the specular propagation paths, after which the remainder was regarded as the diffuse spectrum. The behavior of the reverberation time, known from the theory of room electromagnetics, was analyzed based on this diffuse spectrum.
09:20 A Comparison of Indoor Channel Properties in V and E Bands
Aliou Bamba (CEA LETI - Université Grenoble-Alpes, France); Francesco Mani (Università degli studi di Bologna, Italy); Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France)
This paper presents wideband channel measurements in an office environment in the 62 GHz and 83 GHz frequency bands. Measurements were performed with a VNA and the mechanical steering of directive antennas at both the transmitter and receiver side, allowing a double-directional angular characterization. A comparison of propagation characteristics such as the path loss, multipaths clusters' dispersion properties in the delay and angular domains are provided. Results show that similar propagation characteristics are attainable in the two bands considered.
09:40 11 GHz Band MIMO Channel Characteristics in a Street Micro-Cell Environment
Kentaro Saito and Jun-ichi Takada (Tokyo Institute of Technology, Japan); Minseok Kim (Niigata University, Japan)
Recently, the fifth-generation mobile communication system (5G) has been widely investigated to accommodate increasing mobile users' traffic. In the 5G system, although the utilization of the higher frequency band above the 6 GHz band is expected, the detailed investigation for the applicability to the mobile communication is still necessary because of different radio channel characteristics compared with microwave bands. In this paper, 11 GHz band MIMO channel measurements were conducted in a street micro-cell environment. The result shows that the delay and the angular spreads of the specular paths were smaller compared with the results in the microwave band. The scattered signal component was weak compared with measurement results of indoor environments. The result is expected to utilize for the MIMO channel modeling in the higher frequency band.
10:00 Indoor Channel Characteristics in Atrium Entrance Hall Environment at Millimeter-wave Band
Minseok Kim, Tatsuki Iwata and Kento Umeki (Niigata University, Japan); Jun-ichi Takada (Tokyo Institute of Technology, Japan); Shigenobu Sasaki (Niigata University, Japan)
This paper presents indoor channel characteristics in atrium entrance hall environment at millimeter-wave band. In this measurement campaign, the base stations (BS) were mounted at a height of approximately 2.8 m on the walls and the user equipment (UE) was located at multiple positions on the floor.
10:20 Coffee Break
10:50 A Model for the Reflection of Terahertz Signals From Printed Circuit Boards
Alexander Fricke and Thomas Kürner (Technische Universität Braunschweig, Germany); Mounir Achir (Canon Research Centre France, France); Philippe Le Bars (Canon CRF, France)
Based on Vector Network Analyzer (VNA) measurements, a model for the specular reflection behavior of printed circuit boards (PCB) in the Terahertz range has been derived. It has been calibrated to suit the behavior of the measurements using a simulated annealing algorithm. The model has been tailored for the integration to ray-tracing based propagation modeling.
11:10 Comparison of Path Loss Models for Indoor 30 GHz, 140 GHz, and 300 GHz Channels
Chia-Lin Cheng and Seunghwan Kim (Georgia Tech, USA); Alenka Zajic (Georgia Institute of Technology, USA)
This paper compares performance of the single-frequency floating-intercept model, the single-frequency close-in model, the multi-frequency alpha-beta-gamma model, and the multi-frequency close-in frequency-dependent model at 30 GHz, 140 GHz, and 300 GHz. For comparison purposes, extensive propagation measurements at 30 GHz (26.5--40 GHz), D-band (110--170 GHz), and 300 GHz (300--316 GHz) are conducted in the indoor line-of-sight (LoS) environments. The results show that if no measurement error is present in the channel impulse response, all four models have very similar performance and the model with the smallest number of parameters would be the optimal choice. On the other hand, the results show that in the presence of measurement errors or lack of detailed antenna gain characterization, models without physical anchor outperform models with physical anchor and correctly predict the reason for path loss mismatch between model and theoretical values.
11:30 Investigations on Fading Scaling with Bandwidth and Directivity at 60 GHz
Diego Dupleich (Ilmenau University of Technology, Germany); Naveed Iqbal (Huawei Technologies, Germany); Christian Schneider (Ilmenau University of Technology, Germany); Stephan Haefner (Technische Universität Ilmenau, Germany); Robert Müller and Sergii Skoblikov (TU Ilmenau, Germany); Jian Luo (Huawei Technologies Duesseldorf GmbH, Germany); Reiner S. Thomä (Ilmenau University of Technology, Germany)
In the present paper we analyse small-scale fading of reflections at 60 GHz using different antennas and bandwidths. The aim is to investigate the deterministic property of the channel in view of modelling and deployment of systems with larger bandwidths and higher directivity. We have investigated the scattering effect of a reflection on a wall emulating a beam-former in a NLOS condition. The results show that the distribution of the amplitudes fit better with a Rician than a Rayleigh distribution. Furthermore, we show that an increasing bandwidth and directivity increases the K-factor, supporting the idea of deterministic paths apart from the LOS.
11:50 Multi-frequency Power Angular Spectrum Comparison for an Indoor Environment
Usman Tahir Virk, Sinh Nguyen and Katsuyuki Haneda (Aalto University, Finland)
This paper presents the comparison of power angular spectra at frequencies below and above 6 GHz, i.e., 2, 15, 28, 60 GHz. With the increased focus on millimeter wave frequencies for ultra-high data rates, a detailed understanding of channel frequency dependence has become crucial. The analysis in this paper is based on multi-frequency radio channel measurements in an indoor coffee room environment for both line-of-sight (LOS) and non-LOS scenarios. For multipath extraction, two different methodologies are used at below and above 6 GHz frequency bands, respectively. The results indicate that LOS channels demonstrate a similar spatial spread at all the frequencies considered, and hence can be spatially modeled in a similar fashion. The NLOS channels exhibit larger spatial spread overall. The paths at above 6 GHz channels appear to be spatially more consistent compared to those that are below 6 GHz, where penetrated and the diffracted paths also exist.
12:10 Path Loss Model in Typical Outdoor Environments in the 50-73 GHz Band
Sana Salous, Xavier Raimundo and Adnan Cheema (Durham University, United Kingdom (Great Britain))
Results of path loss in typical outdoor environments in two frequency bands identified in WRC15 for future 5G radio systems are presented. These include angular path loss as estimated from the strongest component, the main beam, the back beam and from the synthesized omni-directional beam.

#### CS29 New Antenna Systems Involving Application of Metamaterials and Metasurfaces (IET)

Future Applications / Convened Session / Antennas
Oral Sessions: Room 351
Chairs: Rob Lewis (BAE Systems Applied Intelligence Laboratories, United Kingdom (Great Britain)), Hisamatsu Nakano (Hosei University, Japan)
08:40 Characterization of the Efficiency of Metasurface Antennas
Gabriele Minatti (Wave Up S. r. l. & University of Siena, Italy); Enrica Martini (University of Siena, Italy); Marco Sabbadini (Esa Estec, The Netherlands); Stefano Maci (University of Siena, Italy)
Efficiency of modulated metasurface (MTS) antennas is investigated from a theoretical point of view. The MTS antennas we consider are formed by a dense texture of capacitive elements printed on a dielectric slab, backed by a ground plane and fed by a single point source. This is a common configuration for MTS antennas working at the microwave frequencies. We provide compact expressions for the efficiency of MTS antennas and useful indications for their design.
09:00 A Tunable Polarization Rotator Based on Metasurfaces
Zhanni Wu (University of Michigan, Ann Arbor); Younes Ra'di (University of Texas at Austin, USA); Anthony Grbic (University of Michigan, Ann Arbor, USA)
An electronically tunable polarization rotator based on tensor metasurfaces is reported. For a linearly polarized incident wave, the polarization tilt angle can be arbitrarily controlled through a simple biasing mechanism. The proposed metasurface design allows global phase and polarization control simultaneously.
09:20 Frequency Selective Surface Loaded Antenna for Direct Antenna Modulation
Stephen Henthorn, Kenneth Lee Ford and Timothy O'Farrell (University of Sheffield, United Kingdom (Great Britain))
A reconfigurable antenna loaded with Frequency Selective Surfaces (FSS) to achieve direct antenna phase modulation is presented and simulated. Placing FSS with integrated varactor diodes into a monopole-fed cavity allows control of the transmitted phase of a carrier signal with a bias voltage. As such, Direct Antenna Modulation (DAM) can be achieved, producing a phase modulator that can be included in a low complexity transmitter. Simulation shows such an antenna can achieve QPSK modulation with between 3.5dB and 4.5dB magnitude variation between constellation points with acceptable phase stability with radiation angle in the antenna 3dB beamwidth.
09:40 Emulating Arbitrary Antenna Arrays with Low-Profile Probe-Fed Cavity-Excited Omega-Bianisotropic Metasurface Antennas
Ariel Epstein (Technion - Israel Institute of Technology, Israel); George V. Eleftheriades (University of Toronto, Canada)
We present a methodology to design cavity-excited omega-bianisotropic metasurface (O-BMS) antennas capable of producing arbitrary radiation patterns, prescribed by antenna array theory. The method relies on previous work, in which we proved that utilizing the three O-BMS degrees of freedom, namely, electric and magnetic polarizabilities, and magnetoelectric coupling, any field transformation that obeys local power conservation can be implemented via passive lossless components. When the O-BMS acts as the top cover of a metallic cavity excited by a point source, this property allows optimization of the metasurface modal reflection coefficients to establish any desirable power profile on the aperture. Matching in this way the excitation profile to the target power profile corresponding to the desirable aperture fields allows emulation of arbitrary discrete antenna array radiation patterns. The resultant low-profile probed-fed cavity-excited O-BMS antennas offer a new means for meticulous pattern control, without requiring complex, expensive, and often lossy, feed networks.
10:00 Overcoming Traditional Electrically Small Antenna Tradeoffs with Meta-Structures
Richard W. Ziolkowski (University of Arizona, USA); Ming-Chun Tang (College of Communication Engineering, Chongqing University, Chongqing, P.R. China)
Metamaterial-inspired near-field resonant parasitic (NFRP) electrically small antennas (ESAs) have been designed and experimentally validated to have not only high radiation efficiencies, but also multi-functionality, large bandwidths, high directivities and reconfigurability. These expanded capabilities have been attained by introducing more complex meta-structures, i.e., multiple NFRP elements loaded with fixed and tunable lumped elements, as well as active circuits. Different classes of passive and active NFRP ESAs that have successfully produced these effects will be reviewed, and several recently reported ESA systems will be introduced and discussed.
10:20 Coffee Break
10:50 Metaline-based Antennas
Hisamatsu Nakano (Hosei University, Japan)
This paper presents recent developments in metaline-based antennas. Four metalines are presented and application of these metalines to low-profile antennas is discussed: (A) zeroth-order metaline antenna, (B) double metaline antennas, (C) metaloop antennas, (D) metaspiral antennas, and (E) metahelical antennas. Wideband broadside radiation from double metaline antennas and dual-band counter circularly-polarized radiation from the metaloop, metaspiral and metahelical antennas are revealed.
11:10 Tailoring of Electromagnetic Waves by Metasurfaces
Luigi La Spada (Queen Mary University of London, United Kingdom (Great Britain)); Yang Hao (Queen Mary University, United Kingdom (Great Britain))
In the last few years, non-homogeneous meta-surfaces captured huge interest in tailoring electromagnetic waves, ranging from microwave to optical frequencies. Several technologies have been proposed, but a general design approach is still missing: the aim of this work is to present a modeling tool for the control of electromagnetic waves propagations. This approach enables to link the meta-surfaces electromagnetic properties with their geometrical and physical characteristics. To validate the proposed approach, two different applications will be reported: a flat Luneburg Lens and a sharp corner guiding structure. Results show good performance in terms of wide bandwidth and source independence.
11:30 Design of Microwave Components in Groove Gap Waveguide Technology Implemented by Holey EBG
Mahsa Ebrahimpouri and Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden); Eva Rajo-Iglesias (University Carlos III of Madrid, Spain)
In this paper, the feasibility of the implementation of microwave components in groove gap waveguide technology by glide-symmetry holey EBG is discussed. Using this technology, microwave components and antennas which were previously designed for hollow metallic waveguides can be manufactured in a cost-effective way at high frequencies. To show the viability of the proposed solution a phase shifter and a mode converter are designed as examples of typical components for antenna systems.
11:50 Mode Matching Analysis of Two Dimensional Glide-Symmetric Corrugated Metasurfaces
Fatemeh Ghasemifard, Mahsa Ebrahimpouri, Martin Norgren and Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden)
The mode matching method for analysing two dimensional doubled corrugated metasurfaces, including glide-symmetric corrugated metasurfaces, embedded in a thin parallel plate waveguide is presented. This method is accurate, fast, and without any limitations on the parameters.
12:10 Slotted SIW Leaky-Wave Antenna with Improved Backward Scanning Bandwidth and Consistent Gain
N Nasimuddin (Institute for Infocomm Research, Singapore); Zhi Ning Chen (National University of Singapore, Singapore); Xianming Qing (Institute for Infocomm Research, Singapore)
A dumbbell-shaped slotted leaky-wave antenna based on composite right/left-handed metamaterial structure is proposed to improve the backward scanning bandwidth and achieve consistent gain. The antenna consists of substrate integrated waveguide (SIW) unit cells array, which is configured by a dumbbell-shaped slot, cut on the upper layer of the SIW, and an embedded patch underneath the dumbbell-shaped slot. The antenna improves the backward scanning bandwidth compared with the planar-slotted SIW leaky-wave antenna. A measured beam scanning range of -66° to 78° with consistent gain of > 10 dBi is achieved across a frequency range from 7.5 GHz to 13.0 GHz

### Tuesday, March 21, 08:40 - 10:20

#### R_A01 Mm-Wave Radar Antennas

Radars / Regular Session / Antennas
Oral Sessions: Room 352A
Chairs: Erio Gandini (TNO, The Netherlands), Bernard Jecko (XLIM, France)
08:40 A Dielectric Lens Antenna Fed by a Flexible Dielectric Waveguide At 160GHz
Martin Geiger and Martin Hitzler (University of Ulm, Germany); Johannes Iberle (Ulm University of Applied Sciences, Germany); Christian Waldschmidt (University of Ulm, Germany)
Flexible antennas in radar applications enable the user to go around obstacles or detect targets at hidden places. In this paper, two elliptical lenses of different size made of high density polyethylene and stacked on a flexible dielectric waveguide are designed and measured from 140 GHz to 180 GHz. The feeding dielectric waveguide and the mode transition from metallic waveguide to dielectric waveguide was investigated with full wave simulations. The elliptical lenses were designed with a geometrical optics approach. The realized antennas have a gain larger than 24 dBi and 27 dBi and a maximum side lobe level below −15.8 dB.
09:00 Gain Enhancement of a Slot Antenna Using Multiple Metasurfaces
Bilal El Jaafari (Institut d'Electronique et de Télécommunications de Rennes & Institut National des Sciences Appliquées de Rennes, France); Jean-marie Floch (IETR-INSA Rennes, France)
We present in this paper a design of a high gain antenna for radar-based non-contact measurement systems in the k-band frequency. The proposed antenna consists of a slot on a multi-grooved metal structure (flange) and a frequency selective surface (FSS) acting as a flat lens. Often, grooved (or corrugated) surfaces and frequency selective surfaces are used to enhance antenna gain features. The combination of these two techniques could provide more gain with a small size antenna. In this sense, dimensions of both grooves and FSS are optimized to reach the maximum gain without increasing the size of the antenna. All simulations and optimizations are carried out using electromagnetic full-wave tools. Next, a prototype of the proposed antenna is manufactured and characterized. More than 15 dB of gain is obtained over the whole bandwidth with a peak gain of about 17.5 dB is measured around the frequency 24.5 GHz.
09:20 Modeling the Response of Dielectric Slabs on Ground Planes Using CW Focused Millimeter Waves
Mahdiar Sadeghi, Elizabeth Wig, Ann Morgenthaler and Carey Rappaport (Northeastern University, USA)
We present a novel non-iterative model-based on ray analysis to characterize non-metallic, weak dielectric objects (like threat objects) on the surface of a highly conducting background (like the human body) using a focused continuous millimeter-wave sensor. For a simple constant thickness dielectric slab on a ground plane, there are five primary scattering phenomena that must be considered.
09:40 Design of Circular Dual and Quad Ridge Horn Antennas for Millimeter Wave Applications
Nathan Jastram and Conrad Andrews (University of Colorado Boulder, USA); Dejan Filipovic (University of Colorado at Boulder, USA)
The design of circular dual and quad ridged horn antennas covering the 18 to 45 GHz band is discussed. An exponential taper and blending fillet for the ridge profile are presented to minimize 3 dB beamwidth variation while maintaining high boresight gain for both dual and quad ridge horns. Boresight gain for a quad ridge design is greater than 15 dBi, while boresight gain greater than 17.9 dBi is shown for a dual ridge circular horn design. Both horns have axial 3 dB beamwidth variation less than 5 degrees over the entire frequency band.
10:00 Design and Experimental Validation of a Wide Field of View Dual-Lens Antenna at Sub-Millimeter Wave Frequencies
Erio Gandini (TNO, The Netherlands); Aleksi Tamminen and Arttu Luukanen (Asqella Oy, Finland); Nuria LLombart (Delft University of Technology, The Netherlands)
A wide field of view dual-lens system is presented in this contribution. The antenna is designed has to work from 250 to 500 GHz. An outline of the design considerations is discussed. The lens system is designed for near-field focusing, at a range of 2.1 m and can be refocused by displacing one lens in from 1.8 to 2.3 m. The simulated results show that over the required field of view of ±25.4° (±1 m at the nominal range) the gain variation is approximately 3 dB. Moreover, the half power beamwidth at the edge of the field of view increases by only a factor 1.4 compared to the broadside pattern. This makes the design suited for imaging systems since the image resolution is practically constant over the field of view. The dual lens system was fabricated and the measurements confirm the predicted performance.

#### CS45 Smart Beamforming in Far-Field Wireless Power Transmission

Localization & Connected Objects / Convened Session / Antennas
Oral Sessions: Room 352B
Chairs: Diego Masotti (University of Bologna, Italy), Pedro Tavares Pinho (ISEL & ISEL - Instituto Superior de Engenharia de Lisboa, Portugal)
08:40 3D Printed Lens Antenna for Wireless Power Transfer At Ku-Band
Ricardo Gonçalves (Instituto de Telecomunicações - Aveiro & Evoleo Technologies, Portugal); Pedro Tavares Pinho (ISEL & ISEL - Instituto Superior de Engenharia de Lisboa, Portugal); Nuno Borges Carvalho (University of Aveiro/IT Aveiro, Portugal)
In this paper we present the design of an antenna, operating in the Ku-band, conceived for wireless power transfer systems. It comprises an hemispherical dielectric lens, fabricated using 3D printing technology, fed by a microstrip patch antenna array. The conjugation of the dielectric lens with the microstrip patch array allows the development of a compact high gain antenna. The antenna presents a matched bandwidth between 12.7 and 13.15 GHz and a maximum gain of 18.1 dBi at each element.
09:00 Design Methodology for the Multi-Beam Phased Array of Antennas with Relatively Arbitrary Coverage Sector
Hsi-Tseng Chou (National Taiwan University, Taiwan)
This paper presents the design methodology of multi-beam phased array of antennas that may provide high gain and narrow beam radiation patterns within a desired coverage range. The advantages of high energy efficiency in the coverage area provide the flexibility of applications in various area such as wireless power transmission and mobile communications. The relatively flexible mechanism to determine the number of beams, beamwidth and beam directions makes the proposed method very useful in the practical implementation of multi-beam antennas. The methodology is summarized with an example to demonstrate the feasibility.
09:20 Study of Flat Beam in Near-field for Beam-Type Wireless Power Transfer via Microwaves
Naoki Shinohara and Naoki Kamiyoshikawa (Kyoto University, Japan)
This study proposes a simple method for creating flat beam patterns in a near-field. In radio-wave transmission, the near-field beam efficiency of the beam-type wireless power transfer (WPT) system theoretically reaches 100%, but the beam pattern is not flat in the near field. In real beam-type WPT systems, the total beam efficiency (DC-RF-transmission, beam efficiency, and RF-DC conversion) can be improved by increasing the RF-DC efficiency of the rectenna. However, the rectenna requires a flat beam pattern in the near-field. In the present study, we create a flat beam pattern in the near field of a multicopter assisted wireless batteryless sensing system.
09:40 Time-based RF Showers for Energy-Aware Power Transmission
Diego Masotti (University of Bologna, Italy); Alessandra Costanzo (DEI, University of Bologna, Italy)
This paper proposes a review of the use of time-based arrays as RF energy providers in those wireless applications where an energy-aware transmission is of key importance. The higher simplicity and versatility of time-modulated arrays (TMAs) with respect to other modern radiating systems is deeply discussed: in particular, the multi-harmonic radiation capability of TMA is efficiently deployed in the smart wireless power transfer procedure. This two-step procedure is demonstrated through a 2.45 GHz 8-monopole planar array, by resorting to a rigorous co-simulation approach: it combines the Harmonic Balance technique, for the accurate description of the nonlinear switches, with the full-wave analysis of the array and its feeding network.
10:00 Transient Directed WPT
Hubregt J. Visser (imec The Netherlands, The Netherlands)
The use of an array antenna, transmitting pulsed signals and applying time-delays between the elements to create an area of high power density in front of the array at a prescribed position at a chosen moment in time is discussed. Using realistic bandwidths and pulse repetition frequencies leads to the creation of undesirable hot spots. Replacing the array elements with small phased array antennas proves to cure this phenomenon.

### Tuesday, March 21, 08:40 - 12:30

#### CS04 Advanced Statistical Methods and Tools in Applied Electromagnetism

Methods & Tools / Convened Session / Propagation
Oral Sessions: Room 353
Chairs: Philippe De Doncker (ULB, Belgium), Raj Mittra (Penn State University, USA)
08:40 Surrogate Models for Uncertainty Quantification: An Overview
Bruno Sudret and Stefano Marelli (ETH Zurich, Switzerland); Joe Wiart (Telecom ParisTech, France)
Uncertainty quantification has become a hot topic in computational sciences in the last decade. Indeed computer models (a.k.a simulators) are becoming more and more complex and demanding, yet the knowledge of the input parameters to feed into the model is usually limited. Based on the available data and possibly expert knowledge, parameters are represented by random variables. Of crucial interest is the propagation of the uncertainties through the simulator so as to estimate statistics of the quantities of interest. Monte Carlo simulation, a popular technique based on random number simulation, is unaffordable in practice when each simulator run takes minutes to hours. In this contribution we shortly review recent techniques to bypass Monte Carlo simulation, namely surrogate models. The basics of polynomial chaos expansions and low-rank tensor approximations are given together with hints on how to derive the statistics of interest, namely moments, sensitivity indices or probabilities of failure.
09:00 Statistical Analysis of Electromagnetic Structures and Antennas Using the Polynomial Chaos Expansion
Hulusi Acikgoz (KTO Karatay University, Turkey); Raj Mittra (Penn State University, USA)
Electromagnetic (EM) structures such as antennas, resonators, are widely used in EM communication systems. It is not uncommon to find that the performance characteristics of these structures are not as expected because of the uncertainties introduced during the manufacturing process. These uncertainties may arise, for instance, from variations of the dimensions of the device or its material properties, e.g., permittivity and permeability. A statistical tool based on the use of the Polynomial Chaos Expansion (PCE) technique is proposed in this work. The results of investigation of two EM structures, namely an E-shaped patch antenna and a split-ring resonator (SRR), are presented as examples. The results confirm that the variability of the design parameters must be taken into account while designing such structures. A sensitivity analysis is also performed in order to determine the most influential parameters that affect the performance of the studied structures.
09:20 Sensitivity Analysis of the Time Transient Currents Induced Along Thin Wires Buried in Lossy and Uncertain Environments
Sébastien Lalléchère (Université Clermont Auvergne, France); Silvestar Sesnic (University of Split, Croatia); Pierre Bonnet (Blaise Pascal University, France); Khalil El Khamlichi Drissi (Universite Blaise Pascal & LASMEA Laboratory, France); Françoise Paladian (Blaise Pascal University, France); Dragan Poljak (University of Split, Croatia)
This contribution aims to assess the sensitivity of the time domain response of a straight thin electrode buried in a lossy half-space. The issue is of crucial importance in many fields including electrical engineering (e.g. ground penetrating radar purposes, lightning protection for electrical settlements). Indeed, such systems are subject to more and more complex radiating coupling, mostly due to the variability of input parameters. An alternative approach to classical Sobol' indices is proposed here, jointly with an advanced analytical resolution of Pocklington integro-differential equation.
09:40 Statistical Analysis and Surrogate Modeling of Indoor Exposure Induced from a WLAN Source
Yenny C Pinto (Institut Mines Telecom, Telecom ParisTech, France); Joe Wiart (Telecom ParisTech, France)
This paper is focused on the statistical analysis of the human indoor exposure induced by a WLAN source (often named "box") located close to the walls of a room of 3*4 m2. The exposure is firstly assessed by using a hybridize method combining the spherical wave description and the FDTD numerical method. A scenario, where the anatomical model is located in unknowing room position and the source is near to the wall but in an unknowing position is analyzed. Due to the variability of this scenario, the entire possible configurations cannot be calculated with the FDTD. A statistical method based on Polynomial Chaos is therefore discussed and used to build a surrogate model allowing to assess the exposure distribution.
10:00 Statistical Evaluation of the Tissue Specified Specific Absorption Rate Using Principal Component Regression
Tongning Wu and Congsheng Li (CATR, P.R. China)
This study focused on the evaluation of the tissue specified specific absorption rate (TSSAR) for a wide frequency band. Principal component regression was used to fit the model using six anatomical and dielectric factors. The results demonstrated that the method could effectively reduce the dimension of the variables and the fitted model for one frequency was applicable to other frequencies.
10:20 Coffee Break
10:50 Advanced Statistical Methods Applied to a Simplifed Assessment of Population Exposure Induced by a LTE Network
Yuanyuan Huang (Télécom Bretagne, France); Nadège Varsier and Zwi Altman (Orange Labs, France); Thomas Courtat (Télécom ParisTech, France); Philippe Martins (Telecom Paristech, France); Laurent Decreusefond (Telecom ParisTech & LTCI, France); Christian Person (Lab-STICC/MOM UMR CNRS, France); Joe Wiart (Telecom ParisTech, France)
This study presents a simplified methodology based on advanced statistical tools to evaluate the day-to-day global electromagnetic (EM) field exposure of a population taking into account the variability and uncertainties linked to propagation environment, information and communication technology usage, as well as EM fields from personal wireless devices and base stations. A sensitivity analysis was carried out in order to assess the influence of these parameters on EM field exposure. Results have highlighted the importance of received power density from base stations to the issue of global exposure induced by a macro LTE network for an entire population in an urban area.
11:10 Propagation of Uncertainty in the MUSIC Algorithm Using Polynomial Chaos Expansions
Thomas Van der Vorst (Université Libre de Bruxelles, Belgium); Mathieu Van Eeckhaute (Université libre de Bruxelles (ULB), Belgium); Aziz Benlarbi-Delaï (Sorbonne Universités, UPMC Paris 06, France); Julien Sarrazin (University of Pierre & Marie Curie UPMC, France); François Horlin (Université libre de Bruxelles, Belgium); Philippe De Doncker (ULB, Belgium)
Polynomial chaos expansions are used to analyze the propagation of uncertainties on array parameters in Angle-of-Arrival estimation performed by the MUSIC algorithm.
11:30 Generalized Polynomial Chaos Paradigms to Model Uncertainty in Wireless Links
Marco Rossi, Dries Vande Ginste and Hendrik Rogier (Ghent University, Belgium)
A stochastic framework is proposed to evaluate the effect of random effects on the overall performance of wireless links. A generalized polynomial chaos expansion is leveraged to relate the uncertainties in antenna geometry, orientation and position to the figures of merit characterizing the link. The stochastic testing procedure is proposed as a more efficient alternative to stochastic collocation, for a large number of random variables. The non-intrusive statistical framework is applied to evaluate the uncertainty on the efficiency of a wireless power transfer system.
11:50 Adding Diffuse Scattering Correlation to Effective Roughness Models in Ray Tracing
Yang Miao (Catholique Universite de Louvain, Belgium); Quentin Gueuning (Université Catholique de Louvain, Belgium); Mingming Gan (AIT Austrian Institute of Technology GmbH, Austria); Claude Oestges (Université Catholique de Louvain, Belgium)
This paper proposes to add diffuse scattering correlation to Effective Roughness (ER) models used in ray tracing. Diffuse scattering correlation is modeled by phase evolution models including a deterministic part and a correlated (random) part. The deterministic part is dependent on the distance variations between the moving terminal and each ER tile, and the correlated part is related to the angular variations. The predicted narrowband radio channels by ray tracing with proposed diffuse scattering correlation are compared with those obtained by applying a reference physical optics approach, in terms of the Doppler properties over spatial frequency.
12:10 Preliminary Statistical Analysis of Four Site Diversity Experiment at Ka-band
Arsim Kelmendi and Andrej Vilhar (Jozef Stefan Institute, Slovenia)
This paper describes the ongoing site-diversity experiment, consisting of three beacon receiver stations in Slovenia and one station in Austria. All the four stations are identical in configuration and are measuring the 20.2 GHz beacon signal, transmitted from the ASTRA 3B geostationary satellite. The stations were gradually deployed in the years 2014 and 2015. The measured attenuation time series and joint attenuation time series are obtained and statistically analysed. The results are presented in two parts: a) for one full year of collected data from the three Slovenian stations, and b) for seven months of recently collected measurement data in the four-site constellation, including the Austrian station. The results confirm the benefits of site diversity system in terms of significant attenuation reduction. They are compared also to the existing ITU-R and the recently proposed Gaussian copula prediction models and the agreement is satisfactory.

### Tuesday, March 21, 08:40 - 10:20

#### F_A04 Submillimeter-wave & Terahertz antenna

Future Applications / Regular Session / Antennas
Oral Sessions: Room 362/363
Chairs: Luis-Enrique Garcia-Muñoz (University Carlos III of Madrid, Spain), Nuria LLombart (Delft University of Technology, The Netherlands)
08:40 Analytical Study of Free-Space Coupling of THz Radiation for a New Radioastronomy Receiver Concept
Gabriel Santamaria Botello and Kerlos Atia Abdalmalak (Universidad Carlos III de Madrid, Spain); Maria-Theresa Schlecht (Universitaet Erlangen-Nuremberg, Germany); David González-Ovejero (Centre National de la Recherche Scientifique - CNRS, France); Florian Sedlmeir, Harald Schwefel and Stefan Malzer (Max Planck Institute for the Science of Light, Germany); Heiko Weber (Universitaet Erlangen-Nuremberg, Germany); Daniel Segovia-Vargas (Universidad Carlos III de Madrid, Spain); Darragh McCarthy and John Anthony Murphy (National University of Ireland Maynooth, Ireland); Gottfried H. Döhler (Max Planck Institute for the Science of Light, Germany); Luis-Enrique Garcia-Muñoz (University Carlos III of Madrid, Spain)
In this paper, a scheme for coupling free-space THz radiation into a nonlinear whispering-gallery mode (WGM) resonator is presented. The purpose is to detect the weak THz radiation from the cosmic microwave background (CMB) by up-converting the signal into the optical domain via to the nonlinearity of the medium. Such high-sensitivity receiver has theoretically shown capabilities towards photon counting at room temperature, however, it is critical to efficiently couple the THz radiation into the resonator. Therefore, by using the Schelkunoff-Waterman method (the so called T-matrix method) we perform an analytical evaluation of two different free-space coupling techniques: a free-space Gaussian beam, and a Gaussian beam incident in a silicon lens under total internal reflection. By comparing the excited modes in the resonator, the optimal parameters for each case are given.
09:00 Recent Work on (sub-)mm-wave Ultra WideBand Corrugated Horns for Radio Astronomy
Alvaro Gonzalez and Keiko Kaneko (National Astronomical Observatory of Japan, Japan); Shin'Ichiro Asayama (National Astronomical Observatory of Japan, Chile)
Corrugated horns are widely used in many applications, including radio astronomy, because of their high performance over large bandwidths. However, the always increasing demand for wider frequency coverage cannot be met by traditional conical corrugated horns with typical fabrication constraints at (sub-)mm wavelengths. The usual way to overcome this limitation is to use profiled corrugated horns, such as the 275-500 GHz horn presented in this paper. As an alternative, we propose and demonstrate that conical corrugated horns can achieve ultra-wideband (UWB) performance by changing the depth of corrugations along the horn. A design for the 67-116 GHz band is presented. Fabrication of these two designs is on-going and measurements will be presented at the conference.
09:20 Validation by Power Measurements of a Norton Equivalent Circuit Model for Photoconductive Antennas
Alessandro Garufo and Giorgio Carluccio (Delft University of Technology, The Netherlands); Joshua R Freeman (University of Leeds, United Kingdom (Great Britain)); David Bacon (University of Leeds, The Netherlands); Nuria LLombart (Delft University of Technology, The Netherlands); E. Linfield (School of Electronic and Electrical Engineering, University of Leeds, United Kingdom (Great Britain)); Alexander Davies (University of Leeds, United Kingdom (Great Britain)); Andrea Neto (Delft University of Technology, The Netherlands)
A validation of a recently proposed equivalent circuit model for describing the radiation of photoconductive antennas is shown in this work. The validation is obtained by comparing the power estimated by the model against radiated power measurements of a manufactured prototype. The model describes the feeding mechanism of an antenna provided via a photoconductor gap, when it is optically pumped by a laser, taking into account for the electrical proprieties of the material, for the geometrical sizes of the gap, and for the laser power excitation. Two different measurement setup have been used, in order to verify the accuracy of the measurements. In order to compare the estimation of the power predicted by the model and the measurements, an evaluation of the efficiencies involved in the THz measurement quasi-optical system has been performed for both the setups. A good agreement is achieved between measurements and power estimated with the model.
09:40 A 45º-Inclined Linearly Polarized Probe for Terahertz Mueller Imaging
Xuexuan Ruan, Kung Bo Ng and Chun Kit Wong (City University of Hong Kong, Hong Kong); Huan Yi and Shi-Wei Qu (University of Electronic Science and Technology of China, P.R. China); Chi Hou Chan (City University of Hong Kong, Hong Kong)
This paper proposes a novel terahertz (THz) probe based on a pyramidal-shaped TE10 mode rectangular open ended waveguide (OEWG) integrated with a 45º-inclined linearly polarized (LP) element. The radiating element, deposited on top of the OEWG, is realized using standard printed-circuit and plated-through-hole technologies. The pyramidal fixture, situated beneath the substrate, is made of brass with gold plated. Experimental results show that the proposed probe can present an impedance bandwidth (VSWR ≤ 2) better than 15.2% from 279 to more than 325 GHz. Within the impedance bandwidth, the gain varies from 5.3 to 10.2 dBi and all radiation patterns are symmetric with low cross-polarization and back radiation levels. The proposed probe is a good candidate for Mueller imaging in THz range.
10:00 A Reconfigurable Multilayered THz Leaky-Wave Antenna Employing Liquid Crystals
Walter Fuscaldo and Silvia Tofani (Sapienza University of Rome, Italy); Dimitrios Zografopoulos (CNR-IMM, Italy); Paolo Baccarelli (Roma Tre University, Italy); Paolo Burghignoli (Sapienza University of Rome, Italy); Romeo Beccherelli (Consiglio Nazionale delle Ricerche, Italy); Alessandro Galli (Sapienza University of Rome, Italy)
In this work, the tunable properties of nematic liquid crystals are exploited in order to design a Fabry-Perot cavity (FPC) leaky-wave antenna (LWA) with beam-steering capability at fixed frequency in the THz range. The considered design is a grounded dielectric slab covered with a multistack of alternating layers of low- and high-permittivity dielectric materials, consisting of nematic liquid crystals and alumina thin films, respectively. The former allows for achieving the beam-steering capability at a fixed frequency. Full-wave simulations confirmed the pattern reconfigurability of the device, thus opening very interesting possibilities for the realization of reconfigurable THz antennas.

#### IWS_01: How to design a matching circuit that matches with the measurements?

WG Meetings & Workshops: Room 313/314
Chair: Jaakko Juntunen (Optenni Ltd., Finland)

### Tuesday, March 21, 10:50 - 12:30

#### W_A02 Arrays Antenna for Wireless Networks

Wireless Networks / Regular Session / Antennas
Oral Sessions: Room 341
Chairs: Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy), Patrice Pajusco (TELECOM Bretagne, France)
10:50 Analysis of Hybrid-Passive-Active Phased Array Configurations Based on an SNR Approximation
Matthias Nickel, Onur H. Karabey, Matthias Maasch, Roland Reese, Matthias Jost and Christian Damm (Technische Universität Darmstadt, Germany); Rolf Jakoby (Institute for Microwave Engineering and Photonics, Technische Universität Darmstadt, Germany); Holger Maune (Technische Universität Darmstadt, Germany)
In this work, the impact of different system configurations on the SNR performance of hybrid-passive-active phased arrays is studied. The separation of the functional core components of active arrays into active and passive parts provides the possibility to reduce power consumption, size and cost, which is of interest especially in mobile applications. Power consuming and expensive active components, such as LNAs, can be shared by multiple antenna elements, whereas passive components, e.g. passive phase shifters, are assigned to each antenna element for beam steering. To estimate the performance of such systems, a noise model is derived for a planar M times N, corporate fed array in tile construction. With this model, it is possible to determine an optimum array configuration in terms of array size and LNA distribution for a given SNR design goal and a given set of limiting factors.
11:10 Feasibility of Dual-polarized Antenna Arrays for GNSS Receivers at Low Elevations
Maysam Ibraheam (Ilmenau University of Technology, Germany); Bjoern Bieske (Institute for Mechatronics and Microelectronic Systems GmbH, Germany); Kurt Gerd Blau (Technische Universität Ilmenau, Germany); Eric Schäfer (Ilmenau University of Technology, Germany); Andre Jäger (IMMS GmbH, Germany); Safwat Irteza Butt (Robert Bosch GmbH, Germany); Ralf Stephan (Technische Universität Ilmenau, Germany); Matthias Hein (Ilmenau University of Technology, Germany)
A dual-band dual-polarized compact antenna array is designed for intended use in robust global navigation satellite receivers. The four-element antenna array is connected to an eigenmode-based decoupling and matching network to compensate for the radiation efficiency degraded by mutual coupling. The resulting eigenmodes of the array are then fed to an RF-IF front-end for down-converting, filtering, and power amplification. Finally, the signals are carried to a digital receiver for decoding and tracking. Field measurements proved the usability of certain left-hand circular polarized modes for receiving the navigation signals, particularly at low elevations. This possibility enhances the receiver robustness against polarization distortion caused by multipath, and thus improves the tracking accuracy. Measurements help also to decide which left-hand modes should be selected for a practical dual-polarized receiver if the number of channels available for array signal processing is limited.
11:30 Synthesis of Clustered Linear Arrays Through a Total Variation Compressive Sensing Approach
Nicola Anselmi (ELEDIA Research Center, Italy); Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy); Andrea Massa (University of Trento, Italy)
In this work the problem of synthesizing the excitations of a linear array, clustered into contiguous sub- arrays of irregular length, is addressed. By suitably exploiting the behavior of clustered array aperture distributions (i.e., step-wise discrete functions), the problem has been formulated as the minimization of the total variation (TV) of the excitations, satisfying a matching condition on a predefined reference pattern. In virtue of the sparse nature of the unknowns, the minimization problem has been solved by means of an efficient total variation compressive sensing (TV- CS) optimization approach. A simple example validating the proposed technique is finally reported.
11:50 Massive Antenna Array for Space Time Channel Sounding
Patrice Pajusco (Telecom Bretagne); Francois Gallée (Télécom Bretagne, France); Nadine Malhouroux (France Telecom Research & Development, France); Roxana Burghelea (Telecom Bretagne, France)
In this paper, a prototype of a dual-polarized array antenna is presented. This array was designed in the framework of a collaborative project on spatial modulation scheme. It will be used for the project testbed and for space-time channel measurements. This array includes several novelties such as a slant uniform planar structure, scalable design including integrated switching circuitry, along with a reference antenna and a camera. The array has been successfully used with a wideband channel sounder to provide real-time radio photos.
12:10 Pattern Recovering of Conformal Antenna Array for Strongly Deformed Surfaces
Francesco Rigobello (University of Padova, Italy); Giulia Mansutti (Università degli Studi di Padova, Italy); Muhammad Saeed Khan and Antonio-D. Capobianco (University of Padova, Italy)
Pattern recovering of conformal phased array on changing surfaces is receiving an increasing attention in the last years. This paper presents the pattern recovery of a strongly deformed conformal phased-array using the projection method. A 4 × 4 flat array is placed on a doubly curved surface. The phase compensation technique is applied first on rows, and then, considering rows as single antenna elements, on array columns. This technique was proved to be effective in recovering direction and width at half maximum of the pattern main lobe and in suppressing side lobes. Analytically predicted recovered patterns are confirmed through full-wave numerical simulations.

#### R_P04 RCS Models

Radars / Regular Session / Propagation
Oral Sessions: Room 352A
Chairs: Christophe Craeye (Université Catholique de Louvain, Belgium), Fernando Las-Heras (Universidad de Oviedo, Spain)
10:50 Monostatic RCS of Electrically Large Structures Using Higher-Order MLFMM
The monostatic radar cross section (RCS) is an important design parameter for many applications, but accurate RCS prediction of an electrically large structure continues to be a challenging task. High accuracy demands and a complicated geometry often mean that asymptotic methods are not applicable, while a full-wave method has traditionally required very large computational resources. In the present paper, we avoid the $f^6$ computational time scaling of the Method of Moments by applying the Multi-Level Fast Multipole Method (MLFMM). A range of modifications to the traditional way of applying MLFMM to monostatic RCS are implemented in order to achieve strong computational performance even on modest hardware.
11:10 Modeling of Bistatic Scattering from the Anisotropic Earth Surfaces
Davide Comite (Sapienza University of Rome, Italy); Franco Fois (Delft University of Technology, The Netherlands); Nazzareno Pierdicca (Uni Roma1, Italy)
Approximate numerical modeling of microwave bistatic scattering (BS) from anisotropic rough surfaces, simulating large baselines radar bistatic system, is analyzed in this contribution. The investigation is performed in the framework of the SAOCOM-CS scientific satellite mission, a small satellite under design by the European Space Agency, to be associated with the Argentinian SAOCOM 1B satellite, aiming at collecting bistatic radar data at L-band. Similar bistatic concepts are being investigated at C-band as well. The main features of the normalized radar cross section (NRCS) of the sea surface in different operating conditions are discussed. This represents the first step to assess the potentiality of bistatic radar observations of natural surfaces with large baseline, and to gather valuable information on the bistatic scattering properties for the design of future spatial missions.
11:30 Spectral Polarimetric Features Analysis of Wind Turbine Clutter in Weather Radar
Jiapeng Yin, Oleg Krasnov and Christine Unal (Delft University of Technology, The Netherlands); Stefano Medagli (TU Delft & Thales, The Netherlands); Herman Russchenberg (Delft University of Technology, The Netherlands)
Wind turbine clutter has gradually become a concern for the radar community for its increasing size and quantity worldwide. Based on the S-band polarimetric Doppler PARSAX radar measurements, this paper demonstrates the micro-Doppler features and spectral-polarimetric characteristic of wind turbine clutter, the probability distribution functions of different spectral-polarimetric variables. Finally, a simple thresholding method to remove wind turbine clutter is put forward, and its effectiveness can be verified by the measured data. This work is expected to contribute to developing effective algorithms for this dynamic clutter suppression for operational weather radar.
11:50 Modular Terrain Modeling with Flexible Conductive Materials in a Scaled Measurement Environment
Björn Neubauer, Robert Geise, Georg Zimmer, Oliver Kerfin and Angela Andree (Technische Universität Braunschweig, Germany); Norbert Ueffing (Piller Germany GmbH & Co. KG, Germany)
Wave propagation over terrain topologies and surface wave propagation relate to several practical applications the simulations of which often become very complex and reach their limits due to the size of objects. Exemplarily, one application is the illumination issue of wind turbines located on different terrains, such as hills in the context of potential bearing errors of the VHF omnidirectional radio range (VOR) due to multipath propagation. Preferably, due to the flexibility of measurements, such investigations are conducted in scaled environments where the object's dimensions are decreased by the same factor the frequencies are increased. This contribution presents the manufacturing process of lightweight, modular pieces with carbon twill fabric on a rigid foam, fastened by epoxy resin using the example of terrain modeling. Corresponding material parameter characterization with radar cross section measurements is carried out. A generic scaled mountain model is constructed and measurements of over-the-hill-propagation are conducted and interpreted
12:10 Analytical Formulation for the micro-Doppler Spectrum for Rotating Targets in the Near-Field
Jean Léger, Thomas Pairon and Christophe Craeye (Université Catholique de Louvain, Belgium)
The analysis of the Doppler signal returned by rotating targets is of great interest in the framework of target recognition and equipment monitoring. An analytical expression of such a signal already exists for the far-field case, based on the Jacobi-Anger expansion. An extension of this analytical expression is proposed for the near-field case. The solution involves a closed-form expression of each harmonic complex coefficient. An error analysis is carried out.

#### L_A02 Wireless Power Transmission and Harvesting II

Localization & Connected Objects / Regular Session / Antennas
Oral Sessions: Room 352B
Chairs: Polina Kapitanova (ITMO University, Russia), Carl Pfeiffer (Defense Engineering Corp & Air Force Research Labs, USA)
10:50 Long Slot Array for Wireless Power Transmission
Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Waleed Alomar (KACST, Saudi Arabia); Anthony Grbic (University of Michigan, Ann Arbor, USA)
Retrodirective antennas used for radiative wireless power transfer (WPT) are typically resonant and exhibit strong backscatter, a limited field of view and small bandwidth. These limitations are here overcome by using an array of long slots fed by parallel plate waveguides (PPWs). It is shown that the array can collect the total power impinging from a remote source over a large field of view and bandwidth. The conclusions arrived at for the infinite case are extended to the finite case through full-wave simulations.
11:10 Retrodirective Antenna Array for Circularly Polarized Wireless Power Transmission
Pascual Hilario Re, Symon K. Podilchak, Samuel Rotenberg and George Goussetis (Heriot-Watt University, United Kingdom (Great Britain)); Jaesup Lee (Samsung Electronics Co., Ltd, Korea)
In this paper, a retrodirective antenna (RDA) array for wireless power transmission (WPT) is presented. Applications include the charging of mobile device batteries wirelessly. Thanks to the principle of phase conjugation in mixers, retrodirectivity can be achieved in the far-field. More specifically, the reported RDA architecture deals with an active transmitter module to retrodirect a received beacon tone, with increased power, from a mobile unit and with circularly polarized (CP) radiation. Measurements and simulations show a good agreement in terms of the retrodirective tracking capabilities. In addition, a new RDA architecture is also proposed for WPT, using sub-arrays, in order to boost the overall received power at the mobile while also not significantly increasing the costs of the active transmitter module. Other applications for the proposed RDA circuit element include target tracking, low-cost sensor charging, and other WPT systems.
11:30 An Efficient RF Energy Harvesting System
Aline Eid and Joseph Costantine (American University of Beirut, Lebanon); Youssef Tawk (The University of New Mexico & Notre Dame University Louaize, USA); Ali Ramadan (Fahad Bin Sultan University, Saudi Arabia); Mahmoud Abdallah, Rena ElHajj, Rayan Awad and Ingrid Kasbah (American University of Beirut, Lebanon)
This paper proposes a new radio frequency (RF) energy harvesting system that operates over the WiFi 802.11 b/g band at low input power levels. The system presented herein achieves good power conversion efficiencies (PCEs) over a power range that extends from (-20 dBm) to (3 dBm). A directive slot antenna is incorporated to drive the rectification process of the designed rectenna. The rectenna system is measured and tested, along with a power management circuitry, for design validation purposes. A good agreement between simulated and measured results is attained.
11:50 On the Design of Frequency Diverse Arrays for Wireless Power Transmission
A-Min Yao (Nanjing University of Science and Technology, P.R. China); Paolo Rocca (University of Trento, Italy); Wen Wu (Nanjing University of Science & Technology, P.R. China); Andrea Massa (University of Trento, Italy)
This paper proposes a frequency diverse array (FDA) design approach, based on nonlinear frequency offsets and time-modulated weights, for far-field wireless power transmission (WPT). The objective is to optimize the frequency offsets and weights across the array elements to provide maximum end-to-end energy transfer efficiency (ETE). A set of numerical examples is reported and discussed to validate the effectiveness of the proposed WPT-FDA approach.
12:10 Colossal Permittivity Resonators for Wireless Power Transfer Systems
Mingzhao Song, Pavel Belov and Polina Kapitanova (ITMO University, Russia)
We propose a colossal permittivity dielectric resonator for magnetic resonant wireless power transfer system.An experimental investigation is performed and the maximal power transfer efficiency is 90% and the efficiency of 50% is achieved at separation between the resonators d=16 cm (3.8 radii of the resonator). The power transfer efficiency as a function of distance, misalignment and rotation angle is calculated. We also fabricate a prototype with a real load of an LED for demonstration.

#### F_A05 Adaptive & Reconfigurable Antennas for Future Applications

Future Applications / Regular Session / Antennas
Oral Sessions: Room 362/363
Chairs: Christophe Fumeaux (The University of Adelaide & School of Electrical and Electronic Engineering, Australia), Adam Narbudowicz (Dublin Institute of Technology, Ireland)
10:50 A Multifunction Antenna with Direct Modulation and Beam Agility
Samir Ouedraogo (SONDRA\CentraleSupélec, France); Israel Hinostroza (SONDRA, Supélec, France); Regis Guinvarc'h (SONDRA, Supelec, France); Raphael Gillard (IETR & INSA, France)
An antenna system simultaneously providing a radar function and a secondary communication function with beam agility is proposed. The system is composed of a slotted waveguide (for the communication function) feeding a horn antenna (for the radar function). Direct modulation in four different directions can be obtained for communication provided each radiating slot is equipped with a simple switch.
11:10 Beamspace Multiplexing for Wireless Millimeter-Wave Backhaul Link
Yuan Ding (Queen's University Belfast & The ECIT, United Kingdom (Great Britain)); Vincent Fusco and Alexey Shitvov (Queen's University Belfast, United Kingdom (Great Britain))
This paper studies the beamspace multiplexing for free-space wireless millimeter-wave (mm-wave) backhaul applications, which has never been investigated before. A system architecture of a dual-beam mm-wave link is established, and the synthesis approach for the system key parameters that enable the beamspace multiplexing is presented. Extensive simulations are performed and the obtained results show a higher spectrum efficiency in the proposed beamspace multiplexing backhaul link than that could be achieved in the single beam system under the constraint of the same transmitted power.
11:30 Realization of a Compact Antenna with Reconfigurable Pattern for Multiple Antenna Systems
Jerzy Kowalewski and Lepold Keller-Bauer (Karlsruhe Institute of Technology, Germany); Tobias Mahler (Karlsruhe Institute of Technology (KIT), Germany); Jonathan Mayer (Karlsruhe Institute of Technology, Germany); Thomas Zwick (Karlsruhe Institute of Technology (KIT), Germany)
A pattern reconfigurable antenna for a multiple-input multiple-output (MIMO) antenna system is presented in this paper. For this antenna a feeding structure, consisting of back-to-back balun, that supports realization of different radiation patterns is proposed. Thanks to novel application of this feeding structure any wanted switchable directivity patterns can be realized. Presented antenna generates two switchable patterns, which are optimized for automotive case. As a proof of concept a prototype of this antenna has been fabricated and measured. In this case p-i-n diodes are used as switching elements. The maximal gain achieved is about 6.5dBi. The measurement results correspond well with the simulation results in terms of S-parameter and radiation.
11:50 The Pattern Selection Capability of a Printed ESPAR Antenna
Leonidas Marantis (University of Piraeus, Greece); Konstantinos Maliatsos (University of Piraeus & National Technical University of Athens, Greece); Christos Oikonomopoulos-Zachos (IMST GmbH, Germany); Dimitrios K. Rongas (National Technical University of Athens, Greece); Anastasios Paraskevopoulos (Loughborough University, United Kingdom (Great Britain) & University of Piraeus, Greece); Antonis Aspreas and Athanasios G. Kanatas (University of Piraeus, Greece)
The research work presented in this paper involves a proof-of-concept indoor experiment that demonstrates the beamforming capability of an Electronically Switched Parasitic Array Radiator (ESPAR) antenna. A new 3-element ESPAR antenna, formed by one active and two parasitic printed monopoles, is proposed. Two prototypes, which operate at 3.55 GHz, are modeled, fabricated and measured, exhibiting a reconfigurable pattern (three operating modes) and a satisfying directivity increase between the omni-directional and the two directional states. The two ESPARs are embedded in a IEEE 802.11p transceiver, in order to perform a beam selection concept in an indoor environment and evaluate the overall performance in a system level. When the two antennas focus their radiations patterns towards each other, an average of more than 6.5 dB Signal to Noise Ratio (SNR) gain is achieved, compared to the omnidirectional mode.
12:10 Concept of a Beam-Steerable Cavity-Fed Antenna with Magnetic-Dipole Coupling Elements
Nghia Nguyen-Trong (University of Queensland, Australia); Andrew Piotrowski (Defence Science and Technology Group (DSTG), Australia); Leonard Hall (Defence Science and Technology Organisation, Australia); Christophe Fumeaux (The University of Adelaide & School of Electrical and Electronic Engineering, Australia)
A concept of a beam-steerable radiator based on a reconfigurable cavity antenna and coupling elements is proposed in this paper. The coupling elements are designed as magnetic dipoles which are realized using half-mode substrate-integrated cavities. Thus, the antenna exhibits vertical polarization in a planar structure. The main beam can be switched among different directions towards end-fire. Furthermore, by using an array of PIN diodes to reconfigure the aperture size of the launching element, the antenna has potential to change its operating frequency. Simulation results are provided as a preliminary demonstration of the concept.

#### WG_02 Small Antennas

WG Meetings & Workshops: Room 313/314
Chair: Pavel Hazdra (Czech Technical University in Prague, Czech Republic)

#### IWS_05: ANSYS Workshop: Antenna Placement and Coupling

WG Meetings & WorkShops: Room 315
Chair: Alain Michel (Ansys France, France)

### Tuesday, March 21, 13:30 - 15:00

#### Poster_01

High Data Rate / Biomedical / Regular Session / Antennas
Room: Poster Sessions: Corridor Neuilly
Chairs: Nader Behdad (University of Wisconsin-Madison, USA), Aziz Benlarbi-Delaï (Sorbonne Universités, UPMC Paris 06, France)
Dispersion Analysis of a Reconfigurable Grounded Slab of Liquid Crystal Loaded by an Inductive Metasurface
Santi Concetto Pavone (Università degli Studi di Siena, Italy); Enrica Martini, Francesco Caminita, Matteo Albani and Stefano Maci (University of Siena, Italy)
The surface wave dispersion of a grounded layer of liquid crystals (LCs) is investigated by taking into account the inherent electrical reconfigurability of such a material. The dyadic impedance Green's function of the tunable LC grounded slab is calculated and the dispersion curve of the fundamental mode supported by the structure is presented, showing that the orientation of the optical axis of the LCs modifies the surface wave dispersion diagram and can be applied for surface wave propagation control. Furthermore, it is demonstrated that the presence of an inductive metasurface (MTS) on top of the LC layer reduces the resonance frequency and increases the sensitivity to the voltage biasing.
Metasurface Antenna Design
Gabriele Minatti (Wave Up S. r. l. & University of Siena, Italy); Francesco Caminita and Enrica Martini (University of Siena, Italy); Marco Sabbadini (Esa Estec, The Netherlands); Stefano Maci (University of Siena, Italy)
This paper summarizes the design method for planar antennas based on modulated metasurfaces (MTSs). These antennas work on a transformation of a cylindrical surface wave (SW) into a leaky wave (LW) through the interaction with the boundary conditions (BCs) imposed by the MTS. The synthesis process allows (i) for determining the BCs that the MTS has to impose in order to reproduce a general aperture field and (ii) for estimating the amount of the input SW power transformed in LW power. Numerical examples are provided as support to the discussion.
Numerical Dispersion and Stability for Three-Dimensional Cylindrical FDTD near the Axis of Rotation
Mohammed F Hadi (Colorado School of Mines, USA & Kuwait University, Kuwait); Atef Elsherbeni (Colorado School of Mines, USA)
The finite-difference time-domain method, when applied in cylindrical coordinates, requires special attention when used in close proximity to a modeled structure's axis of rotation. This paper details the derivation of the numerical dispersion relation and stability criterion of this algorithm. This analysis is instrumental in quantifying simulation error sources and in designing the various ancillary modeling tools.
Properties of Antennas Made with Selective Ag Metallization via Spraying
Arnaud Jammes, Michael Petisme and Koen Staelens (Jet Metal Technologies, France)
This paper starts with the description of a new direct chemical plating method for silver, called the JET METAL (JMT) process and of the JET SELECTIVE process, which allows to obtain a selective metallization on any substrate which can be metallized with the JET METAL process. This technology is based on spraying separately an aqueous solution containing silver metallic ions together with a CMR free, aqueous based reducing agent. This process allows to plate chemical silver at 12 µm/hour at room temperature and at ambient pressure and is already used in industrial processes for metallizing plastics, composites and non-conductive materials in general and this in different formats (3D pieces, 2D foils, …). In the second part, results obtained with metallized antenna patch realized with the process described above are shown and discussed.
Design of Reflective Phase-Shifting Surface for Generating Electromagnetic Vortex Wave
Shixing Yu and Long Li (Xidian University, P.R. China)
A new design of reflective phase-shifting surface for generating an orbital angular momentum (OAM) vortex wave in the radio frequency domain is presented in this paper. The reflective phase-shifting surface consists of single-layer square patches periodically arranged. Theoretical formulations of phase-shift distributions are deduced and used to design the reflective phase-shifting surface producing vortex radio waves. A prototype is designed and simulated to validate the theoretical analysis at 5.8GHz. The simulation results verify that the vortex waves with different OAM mode numbers can be flexibly generated by using the proposed reflective phase-shifting surface. The proposed method paves a way to generate the OAM vortex waves for radio and microwave wireless communication applications.
A Simple and Effective Microwave Invisibility Cloak Based on Frequency Selective Surfaces
Pedro Yuste, Juan M. Rius, Jordi Romeu and Sebastian Blanch Boris (Universitat Politècnica de Catalunya, Spain); Alexander Heldring (Polytechnical University of Catalunya, Spain); Eduard Ubeda (Universitat Politècnica de Catalunya (UPC), Spain)
This paper presents the design, simulation, manufacturing and testing of a simple invisibility cloak based on a frequency selective surface (FSS). The work is focused on cloaking an electrically thin dielectric cylinder with an easy to manufacture FSS made of copper strips glued to the cylinder surface. In contrast to many papers in the literature, the full procedure from formulation to measurement results is presented here. An original approach to obtain the effective surface impedance of the cylindrical FSS from either simulated or measured far fields is introduced. The measurement results show excellent and relatively wide band performance of the cloak prototype.
Low-profile High Gain Antenna Using Patch-patterned Ferrite Metasurface
Jae-Gon Lee and Jeong Hae Lee (Hongik University, Korea)
A novel low-profile high gain antenna using a ferrite metasurface is proposed and designed. The high gain antenna is composed of a patch antenna designed on the perfect electric conductor (PEC) ground plane and the patch-patterned ferrite metasurface. The patch-patterned ferrite metasurface is utilized as a partially reflective surface (PRS) of a patch antenna to increase its gain. A ray theory approach is employed to explain and design the high gain antennas having various heights. The reflection phase of the ferrite metasurface can be controlled by the dimension of a patch on ferrite. In this paper, we have designed the ferrite metasurface having a reflection phase of -90 at the operation frequency of the patch antenna, so that we have designed the high gain antenna with a height of lambda/8.
A Ridge Gap Waveguide Fed Apperture-Coupled Microstrip Antenna Array for 60 GHz Applications
Davood Zarifi (University of Kashan, Iran)
This paper deals with the design of patch antenna arrays with Ridge Gap Waveguides (RGW) feed networks at 60-GHz band. An array of 64 radiating elements are designed and simulated to demonstrate the good performance of the proposed array. The proposed antenna shows the gain up to 22.6 dBi, efficiency higher than 80% and an impedance bandwidth of 13% covering 59-67 GHz. The results are valuable for the design and evaluation of wideband planar antenna arrays at millimeter-wave frequencies.
A Millimeter Wave Antenna with Wide Bandwidth by Using Dielectric Polarizer
Wang Kai Xu and Hang Wong (City University of Hong Kong, Hong Kong)
This paper presents a wideband circularly-polarized millimeter-wave antenna. It consists of a horn antenna and a dielectric substrate. The horn antenna have a wide impedance bandwidth from 50 to 100 GHz for the reflection coefficient below-10 dB. The dielectric substrate is placed above the horn antenna and some rectangular holes are etched from the dielectric substrate to act as a polarizer to transform the polarization of the antenna radiation from linear to circular. The proposed polarizer yields a wide axial ratio bandwidth of 44% from 62 to 97 GHz for the axial ratio below 3 dB. The maximum gain of the antenna can reach to 15 dbic. The proposed polarizer is fabricated by using 3D technology with simple design and low cost.
Antireflective Textured Silicon Optics at Millimeter and Submillimeter Wavelengths
Cecile Jung-Kubiak (NASA-JPL, Caltech, USA); Jack Sayers, Matt Hollister, Arjun Bose, Hiroshige Yoshida, Luke Liao and Jonathan Wong (Caltech, USA); Simon Radford (Caltech, SAO, USA); Goutam Chattopadhyay (JPL, USA); Sunil Golwala (Caltech, USA)
Silicon optics with broadband antireflective (AR) treatments are being developed for millimeter and submillimeter-wave applications, using high resistivity silicon wafers and combined photolithography and deep reactive ion etching (DRIE) techniques. We report on the design, fabrication and testing of single-layer lenses, as well as double-layer lenses, at 250 GHz.
Design of Multiband Segmented Loop Antenna for Unmanned Aerial Vehicle Applications
Dogu Kang and Jaehoon Choi (Hanyang University, Korea)
A multiband segmented loop antenna for unmanned aerial vehicle applications is proposed. The antenna is composed of a segmented loop including eight segments, a patch element, and a shorting strip. The antenna operates with an omnidirectional radiation at 956 MHz because the eight segments are electrically connected with seven capacitive reactances. Due to the addition of both the patch element and shorting strip, the impedance matching characteristic is improved. The proposed antenna has the multiband performance covering GPS L1, GSM1800, GSM1900, UMTS, LTE2300, LTE2500, and 2400 MHz ISM bands. The antenna has quasi-omnidirectional radiation over the above listed frequency bands.
Reduced Ground Plane Aperture-Coupled DRA Fed by Slotted Microstrip for Ultra-Wideband Application
Chemseddine Zebiri (Ferhat Abbas University of Setif, Algeria); Djamel Sayad (University of 20 Aout 1955 - Skikda, Algeria); Nazar Ali (Khaifa University, United Arab Emirates); Mohamed Lashab (University of 20 Aout 55, Skikda, Algeria); Fatiha Benabdelaziz (Université de Mentouri, Constantine, Algerie, Algeria); Raed A Abd-Alhameed (University of Bradford, United Kingdom (Great Britain)); Issa Elfergani and Jonathan Rodriguez (Instituto de Telecomunicações, Portugal)
Two dielectric resonators antenna (DRA) fed through slotted microstrip line for a wideband application is proposed. The two cylindrical DRs are asymmetrically situated with respect to the rectangular coupling aperture center with a defected ground plane. By optimizing the design parameters, two antenna configurations have been achieved: the first covering an impedance bandwidth of about 57%, from 8.02GHz to 14.55 GHz with power gain of 10dBi, and the second having an impedance bandwidth of about 54%, from 8.5GHz to 14.7 GHz, and a power gain of 12dBi. Results of the proposed antennas are presented and discussed.
A Low-profile Parallel Plate Waveguide Slot Antenna Array for Dual-polarization Application
Xianlong Lu, Xiaochuan Wang and Wenzhong Lu (Huazhong University of Science and Technology, P.R. China)
This paper proposes a dual-polarization parallel plate waveguide (PPW) slot antenna array which has the advantages of high efficiency and low-profile. The antenna array is realized in the multilayer structure. The H-plane waveguide arrays in the low layer and the 2×2-element subarray in the upper layer are employed as the feed networks and radiating part, respectively. An 8×8-element array with height of less than 1.2λ0 is designed and simulated. The simulated results show that the bandwidths (|S11|<-10 dB) are about 5.0% (12.05-12.67 GHz) for x-direction and 4.1% (12.08-12.58 GHz) for y-direction polarization. The isolation is better than 25 dB. The antenna efficiencies of more than 80% for both two polarizations are achieved at 12.3 GHz.
Sinusoidal Time-Modulated Uniform Circular Array for Generating Orbital Angular Momentum Modes
Timothy Drysdale (The Open University, United Kingdom (Great Britain)); Ben Allen (University of Oxford & Network Rail, United Kingdom (Great Britain)); Ernest Okon (Thales UK, United Kingdom (Great Britain))
DRAFT VERSION Time Modulated Uniform Circular Arrays (TMUCA) can produce Orbital Angular Momentum (OAM) modes, but typically suffer from leakage of energy into all available OAM modes. This prevents more than one data channel being encoded using OAM modes, and thus prevents full exploitation of the potentially available spectral efficiency. This paper proposes a modified approach that overcomes this limitation, by adopting a time-modulation scheme that relies only on the fundamental harmonic of the time-switching signal, eliminated unwanted spectral and spatial mode leakage. Simulations are presented to support the proposal.
Design of Cassegrain Reflectarray Antenna with Compact Ring Focus Feed
Geng-Bo Wu (UESTC, P.R. China); Shi-Wei Qu (University of Electronic Science and Technology of China, P.R. China); Shi Wen Yang (University of Electronic Science and Technology of china, P.R. China); Chao Ma (UESTC, P.R. China)
A Cassegrain reflectarray antenna using compact ring focus feed is introduced in this paper. The ring focus is formed by the dielectric guide sub-reflector, where the impedance matching can be achieved by adjusting the dimension of the dielectric guide. Also, the actual incidence angles of the coming waves are considered in the design of the reflectarray. A 572-element Cassegrain reflectarray with a low focus-to-diameter rate (F/D) of 0.2 has been designed and simulated. The numerical results demonstrate that this flat Cassegrain reflectarray has achieved aperture efficiency of 33.3% at 12GHz.
A Compact UWB CPW-fed Antenna with Inverted L-Shaped Slot for WLAN Band Notched Characteristics
Athar S. Fazal (CIIT, Pakistan); Usman Nasir and Bilal Ijaz (COMSATS Institute of Information Technology, Pakistan); Khurram S Alimgeer (COMSATS Institute of information Technology, Pakistan); Muhammad Farhan Shafique (COMSATS Institute of Information Technolgy, Pakistan); Raed Shubair (Massachusetts Institute of Technology (MIT), USA); Muhammad Saeed Khan (University of Padova, Italy)
The purpose of this draft is to introduce a compact CPW-fed antenna with WLAN band notched characteristics. For band notched characteristics, an inverted L-shaped structure is used on the surface of radiator. The proposed design has overall size of 25 x 25 x 1.6 mm3 and covers the entire UWB spectrum from 3.02 GHz to 11.34 GHz except the notch band from 4.9 GHz to 6.2 GHz. High concentration of surface current is shown on the inner side of antenna surface and inverted L-shaped stub, when the design is simulated at 5.5 GHz to show the band notch affect. The simulated results in terms of return loss, surface current distribution and VSWR exhibit good antenna performance over the complete spectrum. The validity of the proposed design is also shown by comparing the simulated results with the measured results.
Mutual Coupling Reduction in Dielectric Resonator MIMO Antenna Arrays Using Metasurface Orthogonalize Wall
An effective technique for reducing the mutual coupling between mm-wave dielectric resonator antennas (DRA) using a novel metasurface is investigated and presented. This is achieved by embedding a metasurface wall between the two DRAs, which are placed in H-Plane. Using the proposed metasurface, the TE modes of the antenna become orthogonal which reduces the mutual coupling between the two DRAs. The proposed metasurface wall is composed of 5×4 unit cells along the E-Plane. The mutual coupling is reduced between 4 to 20 dB when the proposed metasurface wall is placed between the antennas. Moreover, the proposed metasurface wall does not have significant impact on the antenna radiation pattern.
Human Exposure to Wireless Power Transfer Systems: a Numerical Dosimetric Study
Rosanna Pinto (ENEA, Italy); Vanni Lopresto (ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Italy); Antonino Genovese (Italian National Agency for New Technologies Energy and Sustainable Economic Development & ENEA, Italy)
Wireless Power Transfer (WPT) technology is one of the most promising application for charging the batteries of electric vehicles. In this framework, the exposure assessment of human body to the stray electromagnetic fields emitted by WPT devices represents a critical issue. In this paper, a methodology for the numerical assessment of the Electric (E)-field induced by WPT systems in exposed people was set up in order to obtain reliable dosimetric results, avoiding high computational costs for simulations. A numerical dosimetric study was carried out to evaluate the electric (E)-field induced in both a homogeneous ellipsoid phantom and in an anatomical human model exposed to a WPT system prototype (delivered power 560 W). Two exposure scenarios were considered employing the anatomical model: the maximum 99th percentile of the induced E-field value in central nervous system was 0.05 V/m and the maximum current density value in the head was 30 mA/m2.
Planning Broadband Train-To-Ground Systems and WiFi Deployments in Subways: Overview and Results
Juan Moreno (Metro de Madrid S.A. & Universidad Politécnica de Madrid, Spain); Carlos Hernández and Carlos Rodríguez Sánchez (Metro de Madrid S.A., Spain); Cesar Briso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain)
Although available for more than ten years, broadband train-to-ground (BTTG) systems have recently become very popular. Railway operators and stakeholders are pressuring to include many communication services inside the train (VoIP, HD-CCTV, onboard WiFi for passengers, signaling, etc.) and to replicate the operational model for stations with remote maintenance and control. In this paper we provide a planning procedure and a discussion for BTTG systems from an industrial perspective. We also provide measurements inside a train car to obtain a channel model useful for WiFi design, and BTTG measurements of signal strength and throughput. Finally, some details about the environment (for testing purposes) are as well mentioned.
Experimental Analysis of Aligment Impact in Short Communications at 300 GHz
Maria-Teresa Martinez-Ingles (University Centre of Defence at the Spanish Air Force Academy, MDE-UPCT, Spain); Davy P Gaillot (University of Lille 1, France); Jose-Maria Molina-Garcia-Pardo, José-Víctor Rodríguez, Juan Pascual-García and Leandro Juan-Llacer (Universidad Politécnica de Cartagena, Spain); Martine Liénard (University of Lille, France)
This work shows preliminary results at 300 GHz, where the effect of misalignment between directive antennas is studied. It is shown than 2 degrees results in a 3 dB loss. Also, multiple specular reflections are found between both antennas at this mmW frequency in such short commutations.
A Copulas-Based Time Series Synthesizer for Mobile Satellite Communications Operating Above 10 GHz
Charilaos Kourogiorgas and Athanasios D. Panagopoulos (National Technical University of Athens, Greece); Rodoula Makri (ICCS, Greece)
In this paper, a synthesizer of rain attenuation time series is presented for a mobile satellite communications system operating at Ku-band and above. In order to support high data rates for mobile terminals in various regions, satellite communication systems could migrate to higher frequency bands. However, the rain attenuation first and second order statistics in mobile satellite systems differ to the fixed stations. Here, an existing copulas-based synthesizer is modified to generate rain attenuation time series and reproduce the statistics of a mobile link under rain. New parameters are extracted and the difference between the first and second order statistics are shown. More particularly, the difference on Kendall's tau parameter, time diversity gain and fade slope statistics between a mobile user and fixed user for a specific scenario are examined.
Statistical Analysis of Instantaneous Frequency Scaling Factor as Derived from Optical Disdrometer Measurements at V/W Bands
Michael Zemba and James Nessel (NASA, USA); Nicholas Tarasenko and Steven Lane (Air Force Research Laboratory, USA)
Since October 2015, NASA Glenn Research Center (GRC) and the Air Force Research Laboratory (AFRL) have collaboratively operated an RF terrestrial link in Albuquerque, New Mexico to characterize atmospheric propagation phenomena at 72 and 84 GHz. The W/V-band Terrestrial Link Experiment (WTLE) consists of coherent transmitters at each frequency on the crest of the Sandia Mountains and a corresponding pair of receivers in south Albuquerque. Alongside the receivers is an optical disdrometer which yields droplet size and velocity distributions (DSD, DVD). In particular, the DSD can be used to derive an instantaneous scaling factor (ISF) by which the measured data at one frequency can be scaled to another - for example, scaling the 72 GHz to an expected 84 GHz timeseries. Given the availability of both the DSD prediction and the directly observed 84 GHz attenuation, WTLE is thus uniquely able assess DSD-derived instantaneous frequency scaling at the V/W-bands.
Multimode Extraction from Dielectric Loaded Waveguides via Method of Moments
Ahmet Aydoğan (Marmara University & Istanbul Technical University, Turkey); Funda Akleman (Istanbul Technical University, Turkey)
Multimodal interactions for inhomogeneously loaded rectangular waveguide are examined. Method of Moments (MoM) is utilized to obtain the scattered field data. Validation of the approach is performed by comparison with mode matching technique.
On the Use of Convex Optimization for Electromagnetic Near-field Shaping
Ioannis Iliopoulos (IETR, University of Rennes 1, France); Benjamin Fuchs (University of Rennes 1 - IETR, France); Ronan Sauleau (University of Rennes 1, France); Philippe Pouliguen (DGA/Direction de la Stratégie, France); Patrick Potier (DGA/Maîtrise de l'Information, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France)
Near-field shaping at microwave or millimeter wave frequencies is an emerging field of study, able to accelerate a variety of technologies. Applications from sensing to medical imaging will benefit from accurate near-field shaping methods. In this communication, the use of convex optimization to shape the near field of a flat radiating aperture is investigated. The proposed approach that is known to provide optimal solutions is compared to existing near-field shaping methods.
Enhancing Breast Cancer Imaging at Millimeter Waves Using Focusing Techniques
Ioannis Iliopoulos (IETR, University of Rennes 1, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Ronan Sauleau (University of Rennes 1, France); Philippe Pouliguen (DGA/Direction de la Stratégie, France); Patrick Potier (DGA/Maîtrise de l'Information, France); Luca Perregrini and Marco Pasian (University of Pavia, Italy)
Medical imaging using electromagnetic waves is a promising field of study, due to its non invasive nature and relatively low cost. Typically, it is pursued at frequencies in the microwave regime to provide adequate penetration depth. However, an increase of the frequency of operation is beneficial in order to improve the resolution, but it is accompanied by increased tissue losses. In this work we investigate the possibility to increase the penetration depth of systems for breast imaging at the lower bound of millimeter waves (30 GHz). The proposed technique consists of a focusing of the field, which provides an important improvement at the achieved imaging depth.
Asymmetric Split Ring Nanosandwich for Refractive Index Sensing
Sara Magdy Kandil (Zewail City for Science and Technology, Egypt); Islam Eshrah (Cairo University, Egypt); Inas El Babli (Faculty of Engineering, Cairo University, Egypt); Ashraf Badawi (Zewail City of Science and Technology, Egypt)
In this paper, we investigate the effect of applying asymmetry to the split ring nanosandwich on its refractive index sensitivity and optical response. Three different asymmetry configurations are studied which are: rotating the upper split ring, tapering the edges and stacking up additional layers to the nanosandwich structure. Each of these configurations shows a significant influence on the sensitivity and spectral response. They also excite different E-field profiles with diverse enhancement locations which make the asymmetric split ring nanosandwich efficient for biosensing applications. A maximum sensitivity of 1953 nm/RIU is obtained at 3916 nm wavelength.
Design and Characterization of a Miniaturized Implantable UHF RFID Tag Based on LTCC Technology
Aleix Garcia-Miquel (University of Barcelona, Spain); Beatriz Medina-Rodríguez (Francisco Albero S.A., Spain); Neus Vidal (University of Barcelona, Spain); Francisco Ramos (Francisco Albero S.A., Spain); Elisenda Roca (Instituto de Microelectronica de Sevilla, Spain); Josep Maria Lopez-Villegas (University of Barcelona, Spain)
This paper presents the design and characterization of a novel, compact, multilayer, passive UHF-RFID tag solution for implantable biotelemetry based on low-temperature co-fired ceramic (LTCC) technology. A spiral planar inverted-F antenna (PIFA) was matched to the UHF integrated circuit (IC) impedance by an inductor line. The LTCC process allowed the IC to be embedded in a sealed cavity. Simulations and measurements of the reflection coefficient and the tag range were carried out when the RFID tag was implanted in the center of a 10 cm cubic skin phantom. The dimensions of the prototype were 8x7x2 mm3, leading to a total volume of 112 mm3. Results indicated a 6 dB bandwidth of 39 MHz and 84 MHz for simulations and measurements, respectively, and a tag range of approximately 10 cm.
Miniaturized Dual-Wideband Circular Patch Antenna for Biomedical Telemetry
Abdelrahman Mohamed (King Fahd University of Petroleum and Minerals, Saudi Arabia); Mohammad S. Sharawi (King Fahd University of Petroleum and Minerals (KFUPM), Saudi Arabia)
A compact dual-wideband circular patch antenna is designed for implanted biomedical data telemetry systems. Several miniaturization techniques were applied to have the resonance at the desired frequencies. The antenna has a radius of 7.5 mm, a thickness of 1.92 mm and a total volume of 340 cubic millimeters. The antenna covers MedRadio (401-405 MHz), MICS (402-405 MHz), and ISM (433.2-434.8 MHz, 2.4-2.5 GHz) bands with a total bandwidth of 685 MHz. The -10dB bandwidth were 351-476 MHz (125 MHz) and 2.26-2.82 GHz (560 MHz). The antenna performance was evaluated in a human tissue model.
Aperture-Coupled Wearable Antenna with Miniature Feeding Network
Jiahao Zhang, Sen Yan and Xiaomu Hu (KU Leuven, Belgium); Guy A. E. Vandenbosch (Katholieke Universiteit Leuven, Belgium)
An aperture-coupled wearable antenna with a miniature feeding network is proposed. In wearable systems, it allows to minimize the dimensions of the rigid Printed Circuit Board (PCB) carrying the electronics and feeding the textile antenna, optimizing the comfort of the user. Simultaneously, it avoids probe feeding, that requires a single soldering point that has a huge risk of being broken with time due to user movements. Since the aperture is implemented on the PCB, it can be fabricated with excellent tolerances. The antenna achieves a miniature feeding network with dimensions of 10 mm × 10 mm (0.0817 λ × 0.0817 λ at 2.45 GHz), while maintaining a good performance in the ISM band. Simulations and experiments agree well, validating the functioning of the antenna.
434 MHz ISM Band Antenna for in-Body Biotelemetry Capsules
Denys Nikolayev (Institute of Electronics and Telecommunications of Rennes, France); Maxim Zhadobov (University of RENNES 1, France); Pavel Karban (University of West Bohemia, Czech Republic); Ronan Sauleau (University of Rennes 1, France)
We propose a versatile 434 MHz in-body capsule antenna suitable for ingestible and variety of implantable applications. The low profile conformal antenna is synthesized using a hybrid analytical-numerical approach and optimized for robust operation at 434 MHz inside a 17 mm long biocompatible encapsulation (7 mm diameter). The antenna remains matched below -10 dB in wide range of body tissues (from 42% of muscle electromagnetic properties up to the maximum tissue electromagnetic properties). A realized gain is -22.4 dBi and radiation efficiency reaches 0.4%. The radiation performance of the proposed antenna exceeds most of counterparts whereas its impedance characteristics are more robust.
Wireless Power Transfer: Are Children More Exposed Than Adults?
Mohsen Koohestani (Institut d'Electronique et de Télécommunications de Rennes - Université de Rennes 1, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Maxim Zhadobov (University of RENNES 1, France)
Aiming at comparing the exposure levels among children and adults, this paper investigates the exposure due to a representative wireless power transfer system in three different human body models, i.e. adult male and female as well as a child. A dosimetry study has been performed to evaluate the exposure levels with respect to the ICNIRP basic restrictions. Differences in terms of dosimetric quantities (E$_{99}$, J$_{1cm^2}$, and local and whole body SAR) has been assessed and reported. Maximum allowable input power has been computed for a representative scenario. It has been found that, for the considered scenario, the exposure due to a resonant WPT system in a child is the same or lower than in an adult. Moreover, the impact of the body dimensions is more pronounced for peak RMS values of E$_{99}$ and J$_{1cm^2}$ compared to those obtained for SAR$_{10g}$ and SAR$_{wb}$. J$_{1cm^2}$ is found to be the most ...
Study on the Compromise Between Resolution and Attenuation for Breast Imaging Systems
Microwave and mm-wave imaging systems for breast cancer detection are pursued to provide an additional technique with respect to current approaches, mostly based x-rays, ultrasounds, and magnetic resonance. The use of non-ionizing radiation and the relatively low cost are among the most important advantages, but often with resolution or attenuation below expectations for microwave and mm-wave systems, respectively. This paper presents a study based on experimental results, for the first time in the frequency range 0.5-50 GHz, where the potential resolution and propagation losses of breast cancer imaging systems are addressed. In particular, the dielectric properties of the human breast are derived from a systematic clinical campaign involving more than 50 patients, who provided more than 200 ex-vivo tissue samples. As an example, the comparison between a system intended to work at 5 GHz and a system designed at 30 GHz is addressed.
Design of 2x2 Array Antenna with Harmonic Suppression Using T-Shape DGS and Spurline
Nurzaimah Zainol, Zahriladha Zakaria and Maisarah Abu (Universiti Teknikal Malaysia Melaka, Malaysia); Mawarni Mohamed Yunus (Universiti Teknologi Malaysia, Malaysia); Eliyana Ruslan (Universiti Teknikal Malaysia Melaka, Malaysia)
In this paper, a new design of 2x2 array antenna with harmonic suppression using defected ground structure (DGS) and spurline has been developed to suppress the undesired signals at harmonic frequency. The results achieve a very good return loss which peaked up to -33.44 dB at 2.45 GHz operating frequency which makes it great promising applications for RF/Microwave energy transfer particularly in suppressing the harmonic that degrade the system performance. The antenna has an extremely high gain which achieved a 14.20 dB with a strong directional radiation pattern; and total efficiency achievement of the 2x2 antenna array is up to 98.86%. Besides that, the excitation of harmonic signals have been suppressed effectively from -29.19 dB to -7.77 dB at frequency of 3.24 GHz and achieved a wider stopband up to 8 GHz. Experimentally, the measured and simulated results are found in an excellent agreement.
Design of Planar Implantable Compact Antennas for Vaginal Sensor for Early Detection of Calving
Imen Ben Trad and Jean-marie Floch (IETR-INSA Rennes, France)
Two implantable antennas radiating at the Industrial, Scientific, and Medical (ISM) frequencies 868 and 915 MHz were proposed to be employed in a vaginal sensor. These structures were developed in the context of the industrial project "Vel'Phone sensor" funded by Medria, a French company for monitoring services. The compact antennas consist on a meander patch and a metamaterial (MTM) -inspired monopole. Both antennas were optimized in free space and in a model of the environment faithful to reality (inside the cow vagina). Prototypes were manufactured and tested using liquid phantom. We proved the potential of the overall system integrated with an electronic card and biocompatible material in real conditions. Simulated and measured results are presented and discussed.
Towards Optimal Noise Properties of NMR Antenna-Receiver Chain
Petar Kolar, Silvio Hrabar and Mihael Grbic (University of Zagreb, Croatia)
A role of a small loop antenna, that acts as a probe in standards NMR systems, is reviewed. It is shown that the noise properties of a whole system are not always dictated just by proper resonant matching of the antenna and the use of high-quality pre-amplifier (as it is usually believed). Actually, the losses and mismatch of all other passive components may have a serious impact on the overall chain sensitivity. A simple theoretical and experimental investigation has shown that careful design of the NMR antenna-receiver chain can substantially decrease the overall noise figure, and therefore increase the system sensitivity.
Wideband Characterization of a Diluted Water Ferrofluid in Presence of a Polarizing Magnetic Field for Application in Biomedicine
Gennaro Bellizzi (University of Naples Federico II, Italy); Gennaro G. Bellizzi (Mediterranea University of Reggio Calabria & IREA - National Research Council, Italy); Ovidio Mario Bucci (University of Naples, Italy)
In this paper we summarize the results of a broadband microwave characterization of the magnetic susceptibility of a diluted water suspension of magnetic nanoparticles, when subject to a polarizing magnetic field of variable strength. In addition, we also present the results of fitting the measured susceptibility with a superposition of relaxation and resonance dispersion models, carried out to get an analytical description of the magnetic response over the entire investigated range of frequencies and polarizing fields. The analysis of the fitting results has shown expected but also unexpected results, whose physical nature deserves further investigation. The presented measurement and fitting results are of particular interest for the implementation and the optimization of some emerging biomedical applications of microwaves and magnetic nanoparticles, such as microwave imaging for the breast cancer diagnostic.
Application of S Parameter to the Inverse Scattering Problem
Yoshihiko Kuwahara (Shizuoka University, Japan)
This paper proposes a method to apply the scattering parameter in the inverse scattering problem. Many researchers may use a vector network analyzer (VNA) as the transceiver in the microwave tomography system. In general, the integral equation for the inverse scattering problem describes relations between the scattered, total, incident field, and the permittivity. In this equation, we cannot apply the scattering parameters, directly. To overcome the problem, we introduce the reciprocity theorem and the circuit theory. The integral equation is rewritten to an equation that relates the observed feed voltage with the permittivity. The effectiveness of the method is demonstrated by a numerical experiment for the microwave mammography
Breast Phantom with a Conductive Skin Layer and Conductive 3D-Printed Anatomical Structures for Microwave Imaging
Bernd Faenger (University Hospital Jena & Institute of Diagnostic and Interventional Radiology, Germany); Sebastian Ley and Marko Helbig (Technische Universität Ilmenau, Germany); Jürgen Sachs (Ilmenau University of Technology, Germany); Ingrid Hilger (University Hospital Jena, Germany)
We present a breast phantom for experimental medical microwave imaging. The phantom structures separating the tissue mimicking liquids are 3D-printed based on conductive materials. The skin is casted by silicone composites with carbon powder and graphite. In comparison to 3D printing with common plastic, this approach allows the simulation of anatomical breast structures with improved dielectric characteristics.
Design of FSS Unit-cell for Energy Concentration on Deep-seated Human Tissue
Woo Cheol Choi, Seonho Lim and Young Joong Yoon (Yonsei University, Korea)
A FSS which allows for a concentration of the EM energy on a deep-seated tissue in the human body is proposed. The unit-cell can change the phase response of the EM wave in a wide phase range, while maintaining the minimum variation of the transmission magnitude. By integrating the unit-cell into the phased-array configuration, the EM energy can be localized into the deep-seated tissue by compensating the phase-delays for different electrical lengths between the FSS-array and the desired target. It leads to the constructive interference of the EM field at the target tissue, so as to deliver strong energy into the human body. The unit-cell consisting of the three-layer metallization is embedded in the water-bolus which provides the optimal condition for the wave-penetration into the complex dielectric media. The FSS unit-cell is analyzed by using the equivalent circuit model and the transmission characteristic is evaluated on the phantom (human body).
Metasurfaces with Positive Reflection Phase Gradients for Broadband Directive Emission
Riad Yahiaoui (Université Paris Ouest Nanterre la Défense, France); Thtreswar Beeharry (UPOND, France); Shah Nawaz Burokur (LEME, France); Patricia Grassin (UPOND, France); Habiba Ouslimani (Université Paris Ouest Nanterre La Défense, France)
Recently, the concept of partially reflecting surface (PRS) with positive reflection phase gradients has been proposed for the design of wideband cavity antennas. In this work, we numerically and experimentally implemented this idea and demonstrated a broadband and highly directive Fabry-Pérot cavity antenna (FPCA) with dual layer PRS at microwaves. Good performance of impedance matching bandwidth (S11 < -10 dB), and a peak directivity of about 17 dB in simulation and less in measurements at around 10 GHz were achieved.

#### Poster_02

Radars / Regular Session / Antennas
Room: Poster Sessions: Corridor Paris
Chairs: Claes Beckman (KTH Royal Institute of Technology, Sweden), Bernard Uguen (University of Rennes I, France)
Wideband Meachanical Scanning Lens Antenna at Ku-Band
Peng-Yu Feng (UESTC, P.R. China); Shi-Wei Qu (University of Electronic Science and Technology of China, P.R. China); Shi Wen Yang (University of Electronic Science and Technology of china, P.R. China)
A wideband mechanical beam steering lens antenna was proposed in this paper. Referring to the operating principle of Risley beam steering system, a fixed beam array antenna was utilized to excite the dielectric wedge lens at Ku-band. By controlling the relative rotation between the feed and the lens, the whole antenna system can scan to ±50° in all directions. The whole profile was integrated to minimum by reducing the feeding distance and the attendant strong coupling effect was suppressed exploiting the multiple layers matching technique. The prototype confirms the feasibility of using array antenna to excite the lens for achieving a low profile, wideband, wide mechanical scanning and high aperture efficiency beam steering antenna.
A Wideband Wide-angle Scanning 1-D Microstrip Patch Array
Xia Run-Liang and Shi-Wei Qu (University of Electronic Science and Technology of China, P.R. China)
Controlling the mutual coupling between array elements is one of the key problems in phased array designs. In this letter, a wideband decoupling network is proposed to suppress the mutual coupling between adjacent array elements. It is shown that the employment of the proposed network leads to a significant improvement of the operating bandwidth under the condition of maintaining a wide scan range, compared with conventional feeding techniques. In this manner, a 1 × 16 stack patch phased array prototype with the proposed decoupling network was fabricated. Measurement results agree well with simulated ones and indicate the effectiveness of the proposed approach in designing a wideband wide-angle scanning phased array.
Increasing Accuracy of Angular Measurements Using UWB Signals
Yury Shestopalov (University of Gävle, Sweden)
We show that dispersion characteristics of antenna patterns should be taken into account when developing systems using UWB signals. The accuracy of measurement of angular coordinates of objects using UWB pulses is increased by optimizing their shape based on known characteristics of the antenna system and at least partially known characteristics of the investigated signal source. Optimization algorithms allow to minimize the width of the directional pattern for a given level of the useful signal.
The Effects of Geometric Scattered Signal Waveform Modeling on Target Identification Performance
Alper M Selver (Dokuz Eylul University, Turkey); Mustafa Secmen (Yasar University, Turkey); Yesim E Zoral (Dokuz Eylul University, Turkey)
Target identification from scattered signals using time domain techniques depend significantly on the waveform. Recently, a structural feature set is proposed which encounter structural properties of the waveform and collects local extrema points to model the scattered signal via triangularization. Then, using this piecewise model, it extracts several morphological features and employs them for target identification through classification. This study expands that approach by modeling the scattered signal with various geometric shapes and accordingly, by enriching the feature set. Such an approach requires careful representation of the waveform model since more than one morphology is considered to represent valleys and hills of the waveform. The effects of this new approach are observed by applications on conducting and dielectric spherical target having different size.
Comparison of Scattered Signal Waveform Recovery Techniques Under Low SNR for Target Identification
Alper M Selver (Dokuz Eylul University, Turkey); Mustafa Secmen (Yasar University, Turkey); Yesim E Zoral (Dokuz Eylul University, Turkey)
Target identification from scattered electromagnetic waves is a difficult problem especially at low SNR levels, which prevents extraction of distinguishable information. When a scattered signal is corrupted by noise, it should be recovered before further processing such as feature extraction and classification. This recovery can be performed in time domain, frequency domain or via time-frequency analysis. In this study, three important techniques are used for distortion correction and their performances are compared. The analyses are performed with both simulated and measured data from various conductor and dielectric targets having different size, geometry and material type.
Some Features of Electromagnetic Scattering by Radially Inhomogeneous DNG Spheres
Alina Gabdullina (Moscow Institute of Physics and Technology, Russia); Olga Smolnikova (Company Radiophyzika, Russia); Sergei P. Skobelev (Radiophyzika, Russia)
A modification of the hybrid projection method developed for analysis of electromagnetic wave scattering by radially inhomogeneous sphere is described. The method is validated for convergence, comparison with appropriate results available in the literature, and for fulfillment of the optical theorem. The method is applied for studying plane wave scattering by Luneburg and Eaton-Lippmann lenses with negative permittivity and permeability. Geometric-optic ray tracing and some results for bistatic and monostatic scattering cross-section for the indicated doubly negative (DNG) lenses of various radii are compared to those of their conventional dielectric analogs.
Some Features of Shaping Narrow Flat-Topped Radiation Patterns by Overlapped Subarrays in Limited-Scan Waveguide Phased Array Antennas
Sergei P. Skobelev (Radiophyzika, Russia); Ivan Makeev (Moscow Institute of Physics and Technology, Russia)
An infinite periodic array of multimode parallel-plate waveguide sections of finite length, each of which is excited by TM modes from a pair of input waveguides, is considered. The array performance is analyzed by the method of projection mode matching on the boundaries of the regions. A few networks of the array excitation are considered for forming overlapped subarrays shaping sector flat-topped radiation patterns. Some numerical results characterizing effectiveness of application of the networks involved for different values of the array element spacing including large enough corresponding to narrow patterns are presented.
Accuracy Improvement of Near-to-Far-Field Transformation in FDTD Calculation
Yiwei He (Osaka Electro-communication University, Japan); Qinglian Guo (Kanazawa Institute of Technology, Japan)
It has been indicated that the accuracy of near-to-far- field (NTFF) transformation in a FDTD computation has a poor accuracy if the cell size is rough than 1/20 wavelength. We investigated the possible reasons that may affect the accuracy of NTFF transformation and found that the averaging approximation of tangential electric and magnetic fields on enclosed Huygens's surface is dominant. In our modified NTFF transformation, the tangential components on the enclosed surface are calculated from the nearby field components with a higher precision. It will be illustrated that the modified method can more accurately calculate the radiation pattern with a cell size of 1/10 wavelength.
Nested Iterative Solutions of Electromagnetic Problems Using Approximate Forms of the Multilevel Fast Multipole Algorithm
Can Onol, Arif Ucuncu, Bariscan Karaosmanoglu and Ozgur Ergul (Middle East Technical University, Turkey)
Nested iterative solutions using full and approximate forms of the multilevel fast multipole algorithm (MLFMA) are presented for efficient analysis of electromagnetic problems. The developed mechanism is based on preconditioning an iterative solution via another iterative solution, and this way, nesting multiple solutions as layers. The accuracy is systematically reduced from top to bottom by using the on-the-fly characteristics of MLFMA, as well as the iterative residual errors. As a demonstration, a three-layer strategy is presented, considering its parametrization for accelerating iterative solutions of perfectly conducting objects. We show that the strategy significantly reduces the solution time, especially for ill-conditioned matrix equations that are derived from the electric-field integral equation.
Optimization of a MIMO Radar Antenna System for Automotive Applications
Claudia Vasanelli and Rahul Batra (Ulm University, Germany); Christian Waldschmidt (Ulm University)
Multiple-Input Multiple-Output (MIMO) radars can improve the angular resolution of automotive radar sensors. In MIMO radars, a critical design parameter is finding the optimal placement of the transmitting and receiving arrays. Indeed, the physical position of the transceivers affects directly the properties of the virtual array. Unfortunately, the inverse mapping from the virtual array to the real transmitter-receiver configuration is still analytically unsolved. In this paper, a genetic algorithm is employed to search the optimal antenna placement. The fitness function exploits the characteristics of the ambiguity function and this allows potentially to control the ambiguity-free region of the antenna system. Numerical and experimental results confirm the suitability of this design procedure.
A Measured FSS Radome with Two Absorptive Bands Separated by One Passband
Weiwei Wu (National University of Defense Technology, P.R. China)
In this paper, a novel FSS radome is developed and measured. This radome has one transparent passband and two absorptive bands. These two absorptive bands are separated by the passband. The radome is manufactured and measured to verify its unique electromagnetic characteristics. In the passband, the gain of the antenna with our radome is only 1~2dB lower than the one of the antenna without any radome. In the absorptive bands, the electric level of the reflected electromagnetic wave from the radome can be 16.5dB lower than the one from a metallic plane with the same size as the radome.
An Efficient Metamaterial-Inspired, Electrically Small Antenna for ISM Band Applications
Sultan Can (Ankara University, Turkey); Kamil Yavuz Kapusuz (Ghent University, Belgium); Asım Egemen Yılmaz (Ankara University, Turkey)
In this study, an electrically small, monopole slot antenna based on near-field resonant parasitic (NFRP) elements composed of metamaterial inspired capacitively loaded loop (CLL) elements is designed and analyzed via a commercial full wave electromagnetic solver. The proposed antenna has an operational frequency of 2.4 GHz and it satisfies the limits of an electrical small antenna (ESA) having a ka value of 0.88. The antenna has a very high efficiency with an overall efficiency value of 95%. The directivity and gain of the proposed antenna is 1.7 dB and 1.45 dB, respectively.
Improving the Radiant Performance of the Antenna with High Impedance Periodic Structure
Guangwei Yang and Jian-ying Li (Northwestern Polytechnical University, P.R. China); Wei Zhang (Northwestern of Polytechnical University, P.R. China)
In this paper, high impedance periodic structure (HIPS) is applied to improve radiation pattern of the antenna element. The working mechanism of HIPS array is investigated. The structure could improve the surface-wave and the broad-beam radiation performance of the individual antenna element. It is benefit for the wide scan performance of the phased array. A microstrip antenna is fabricated and measured. By the comparison to the metal ground plane, the radiation pattern is wider. The measured results of the array coincide with the simulated results.
A Broad-Band Linear-to-Circular Transmission Polarizer Based on Frequency Selective Surfaces
Wei Zhang (Northwestern of Polytechnical University, P.R. China); Jian-ying Li (Northwestern Polytechnical University, P.R. China)
A four-layer square split-rings frequency selective surface is applied for designing a polarization converter. The new proposed polarizer operates in broadband, from 6.4 to 13.7GHz, which can generate circularly polarization waves from incident linearly ones at 45 degree title incidence to the structure. The new polarization converter is optimized and fabricated. Experimental results show that the polarizer takes advantage of both the low insertion loss and the wide 3dB AR bandwidth about 72%.
Single Layer Metasurface Lens Antenna
Daniel Santillán-Haro (Universidad Politecnica de Valencia, Spain); Eva Antonino-Daviu (Universitat Politècnica de València, Spain); Daniel Sanchez-Escuderos (Universidad Politécnica de Valencia, Spain); Miguel Ferrando-Bataller (Universitat Politècnica de València, Spain)
This paper shows how a set of metallic rings can be used as a planar lens to increase the directivity of a single open waveguide. The goal of this antenna is to obtain a high gain over a wide bandwidth, while maintaining a compact size. In order to obtain a physical insight of the radiating behavior, an analysis of the characteristic modes in the metallic ring of the elementary antenna is performed. An efficient optimization process has been carried out in order to find out the optimum dimensions of the antenna. This study is used to improve the return loss level of a single-layer lens, formed by a central metallic ring surrounded by eight small rings, over a resonant ground circular aperture antenna from 3 to 7 GHz and from 10 to 14 GHz.
Investigation of Large Directivity Bandwidth in Multilayer Resonant Cavity Antennas
Affan Baba (Macquarie University, Australia); Raheel M Hashmi (Macquarie University & IEEE, Australia); Karu Esselle (Macquarie University, Australia)
This paper presents results of an investigation carried out on the large directivity bandwidth of a multi-layer all-dielectric resonant cavity antenna (RCA). This RCA comprises of a multi-layer all-dielectric superstructure, which exhibits a measured broadside directivity of 18.1 dBi with an extremely large 3-dB directivity bandwidth of 51%. Unit cell model of the superstructure is studied by employing superstructure reflection model (SRM) and defect cavity model (DCM). This study reveals that by optimising the frequency separation between two positive phase gradients bands generated by resonant cavities, significant improvement in the directivity bandwidth can be achieved.
A Planar Equiangular Spiral Antenna Array for the V-/W-Band
Paul Tcheg, Kolawole D. Bello and David Pouhè (Reutlingen University, Germany)
This work presents a spiral antenna array, which can be used in the V- and W-Band. A 4x4-array equipped with Dolph-Chebychev coefficients is investigated in order to address the issues related to the low gain and side lobe level of the radiating structure. The challenges encountered in this achievement are to provide an antenna that is not only good matched but also presents an appreciable effective bandwidth in presence of a dielectric material at the frequency bands of interest. Its radiation properties including the effective bandwidth and the gain are analyzed for the W-Band.
Planar Tri-Band Antenna Element in L/S/C-Bands
Jan Puskely and Alex Yarovoy (Delft University of Technology, The Netherlands); Antoine Roederer (Technical University of Delft, The Netherlands)
A planar tri-band rectangle-rings microstrip antenna design is presented in this paper. The antenna has three equally tuned resonant bands and also maintains consistent radiation patterns in all the operational sub-bands. The antenna has a single port and its cavity-backed waveguide-like configuration results in minimum mutual coupling levels in antenna array configuration. The antenna element is tuned to operate over the L/S/C radar bands. The antenna is simple and compact structure and measures only 0.25lambda x 0.25lambda at the lowest frequency of operation. Due to its small dimensions, the element is well-suited for application to dense wide-scan phased arrays.
Grating Lobe Suppression in Rotationally Tiled Arrays
Abdullah Alshammary and Stephan Weiss (University of Strathclyde, United Kingdom (Great Britain)); Sultan Almorqi (King Abdulaziz City for Science and Technology (KACST), Saudi Arabia)
Uniform placement of array elements limits its maximum frequency due to the formation of grating lobes. While non-uniform element or subarray spacing have significantly lower grating lobes, it reduces aperture efficiency and leads to arrays that are difficult to design and manufacture. We propose a modular asymmetric convex-shaped subarray to construct the array by rotation and translation, filling the aperture without overlaps or gaps. This new approach can achieve lower grating lobes compared to uniform array geometries. It can also lower design, manufacturing and operation costs by offering interoperable subarrays and provide array size flexibility.
Compact Microstrip Branch-Line Coupler with Unequal Power Division
Denis Letavin, Yury E Mitelman and Victor Chechetkin (Ural Federal University, Russia)
a brief overview of modern methods of miniaturization of microstrip devices is presented. A compact design of the directional coupler, which divides the power with the ratio 1:2, is implemented on a substrate with a relative permittivity ε = 4.4 and thickness h = 1 mm. The proposed layout has a considerably smaller size than the traditional design by using lowpass filters having the same phase differences as the replaced segments. The prototype was manufactured and its parameters were measured. The proposed method of miniaturization has allowed reducing the coupler size by 66% in comparison to standard design.
Wideband Illuminator for Radio Telescope Calibration
John Kot (Young & Kot Engineering Research, Australia); Christophe Granet (Lyrebird Antenna Research Pty Ltd, Australia)
A wideband illuminator antenna with constant effective aperture is developed for use as a calibration source for a radio telescope. Good performance is obtained over a 6:1 bandwidth
Beamwidth Enhancement of On-Chip Antenna Integrated in Single-chip FMCW Radar Using Periodic Dielectric Lenses
Rabia Syeda (University of Technology Eindhoven & Omniradar Eindhoven, The Netherlands); Bedilu Adela and Martijn van Beurden (Eindhoven University of Technology, The Netherlands); Paul Zeijl (Omniradar, The Netherlands); A. B. (Bart) Smolders (Eindhoven University of Technology, The Netherlands)
We demonstrate a compact design for enhancing the 3dB beamwidth of a 60 GHz single-chip millimeter-wave frequency-modulated continuous wave (FMCW) radar with integrated on-chip antennas. We use thin (λfreespace/5) dielectric periodic lenses on top of the epoxy cover of the single-chip radar to change the effective material properties of the epoxy, which changes the field distribution and hence the radiation pattern and beamwidth of the on-chip antennas. The simulation of our periodic lenses with single-chip radar shows an increased H-plane beamwidth of the on-chip antenna by 60% at the center frequency of 60 GHz. Also, the on-chip antenna radiation efficiency is increased by 20%.
Analysis of Linear Fabry-Perot Antennas Excited by Multiple Sources
Filippo Costa and Davide Bianchi (University of Pisa, Italy); Agostino Monorchio (University of Pisa & CNIT, Italy); Giuliano Manara (University of Pisa, Italy)
The properties of Linear Fabry-Perot antennas excited with multiple sources are analyzed. The antenna can be seen of an array of directive subarrays with overlapped regions. The distance and the level of overlapping should be opportunely controlled in order to avoid unwanted coupling among the ports. The antenna is also analyzed via a simple transverse transmission model approach. The method is based on the superposition of the leaky waves excited by each of the applied sources.
SIW H-plane Horn Antenna Loaded with Double Square Loop Structure
Yang Liu (National Space Science Center & University of Chinese Academy of Sciences, P.R. China); Hongjian Wang (National Space Science Center, P.R. China); Fei Xue and Xingchao Dong (National Space Science Center & University of Chinese Academy of Sciences, P.R. China)
This paper presents two novel designs of SIW H-plane horn antenna which are achieved by adding different double square loops as transition structure. The double square loop and its improvement rotated double square loop are adopted to improve the mismatch between the horn and free space. By optimizing the dimensions of the double square loop structure and rotation angle, the impedance bandwidth can be improved to a large extent. The simulation results of the two designed antennas show that bandwidth can be increased to more than 10% with peak gain between 9 and 12 dBi at center frequency. The performance comparisons of the two antennas are also provided in the paper.
Single-layer Sub-wavelength Reflectarray Elements Based on Multiple-Arm Archimedes Spirals
Fei Xue (National Space Science Center & University of Chinese Academy of Sciences, P.R. China); Hongjian Wang and Guang Liu (National Space Science Center, P.R. China); Xingchao Dong and Yang Liu (National Space Science Center & University of Chinese Academy of Sciences, P.R. China)
Single-layer sub-wavelength reflectarray elements structure for broadband operation are presented. The elements are composed of multiple-arm Archimedes spirals and the lattice periods are a quarter of a wavelength at the center frequency of 13.58GHz. By changing the length of arms, about 500° reflection phase ranges are obtained, which is a significant improvement compared to conventional subwavelength elements. Besides, the effects of different incident angles on the multiple-arm Archimedes spirals elements are studied and simulation results indicate that the incident angle has little influence on the reflection phase curve of the elements.
Array Pattern Synthesis by Position Shift Method
Chuang Han and Ling Wang (Northwestern Polytechnical University, P.R. China)
A position shift method (PSM) is presented for uniform planar array pattern synthesis in this paper. This method minimizes the sidelobe level (SLL) by searching the best position solution for every sensor and calculating the pattern with position offset factor. The position offset factor will be calculated by the position shift value without changing the physical geometry. Numerical examples show that the proposed method has a lower SLL of -20.40dB for the 100 element planar array with the main beam width maintained, when compared with the other techniques published in the literature.
Design of Multilayer SIW Cavity-Backed Slot Antenna Array
Yang Cai and Yingsong Zhang (PLA University of Science and Technology, P.R. China); Can Ding (University of Technology, Sydney, P.R. China); Zuping Qian (PLA University of Sci. & Tech., P.R. China); Jie Liu (PLA University of Science and Technology, P.R. China)
In this paper, a multilayer substrate integrated waveguide (SIW) cavity-backed slot antenna array with wideband performance is proposed. In order to broaden the operating bandwidth of SIW slot antenna, multilayer cavities with gradually decreased permittivity and expanded aperture sizes are loaded above the slot, which realizes a smooth transition between SIW slot and free space. A wideband feeding network employing slot coupling is designed to excite the array elements. Results indicate the proposed array operates with 28.4% bandwidth ranging from 22.4 to 29.8 GHz. Besides, stable broadside radiation patterns are obtained across the operating band.
Dual-Loop Line Antennas with Wideband Circular Polarization
Kazuhide Hirose and Yuki Nagata (Shibaura Institute of Technology, Japan); Hisamatsu Nakano (Hosei University, Japan)
We investigate two novel microstrip-line antennas. They are composed of symmetric and asymmetric dual-loop radiation elements, respectively. Based on the radiation characteristics of the symmetric (reference) antenna, the asymmetric (present) antenna is designed using the method of moments. It is found that the present antenna radiates a circularly polarized wave with an axial ratio of less than 3 dB in a frequency bandwidth of 10%, which is wider than that of the reference antenna by a factor of three. The theoretical results are validated by experimental ones.
A Grid Array Antenna Composed of Rectangular Loop Cells Printed on a Dielectric Substrate
Toru Kawano (National Defense Academy, Japan); Hisamatsu Nakano (Hosei University, Japan)
The radiation characteristics of a grid array antenna composed of rectangular loop cells printed on a dielectric substrate (PRecL-GAA) are analyzed using the method of moments. It is found that PRecL-GAA radiates a linearly polarized broadside beam. It is also found that the rectangular loop cell contributes to the reduction of the antenna area, not affecting remarkably the HPBW.
Design of 90-degree Transpolarizing Reflected Surfaces
Misagh Khosronejad and Gian Gentili (Politecnico di Milano, Italy)
Transpolarizing surfaces rotate by 90-degree the polarization of the reflected wave with respect to the incident one. A novel transpolarizing or crosspolarizing surface has been proposed. Two different geometries (for broadband and narrowband scenarios) trans-surfaces have been designed and simulated, providing good results for normal incidence.
Bulk Material Dielectric Property Measurement by an Adapted Free-Space UWB Inverse Scattering Method
David Gibbins (Toshiba Research Europe Limited, United Kingdom (Great Britain)); Tommy Henriksson and Ian Craddock (University of Bristol, United Kingdom (Great Britain))
This paper presents a system to measure the bulk dielectric properties of a non-metallic target. It is intended as a first step towards a multi-antenna pixel type, imaging system using the same principles. The system, based on the free-space method, comprises two Ultra-Wide Band (UWB) antennas submerged in a tank of lossy background liquid. Data is collected by submerging the Object Under Test (OUT) between the antennas and performing a transmission measurement. The dielectric properties of the OUT are recovered using a UWB inverse scattering algorithm. This employs a 3D Electro-Magnetic (EM) simulation of the system that uses a static conductivity material model. The system is calibrated by means of a measurement without the OUT present. Dielectric properties of a range of materials are recovered to within 10 % of the ground truth. Results suggest that a pixel based imaging system may be viable.
Computational Imaging Using Frequency-Diverse Metasurfaces
This paper summarizes the recent advances in using frequency-diverse metasurfaces for computational imaging in the microwave and millimeter wave regimes. Frequency-diverse apertures are defined as structures that can generate distinct radiation patterns as a function of frequency. Such waveforms can multiplex a scene information into a set of backscattered measurements, which can be decoded using computational algorithms. In this manner, these apertures can retrieve a scene's reflectivity map using a fast frequency sweep (all-electronic operation), circumventing the requirement for a mechanical scan or active circuit components. We review recent advances in developing these apertures and examine their performance in both simulation and experimental settings. Finally, efforts to build large apertures, which can image at the diffraction limit, are discussed.
Performance of W-band FMCW Doppler Radar FALCON-A for Arctic Cloud Observations
Toshiaki Takano (Chiba University, Japan)
W-band 95GHz Doppler radar named FALCON-A was developed and installed in Arctic station for cloud observations. Spacial resolution in ranging direction is as high as 10m and beam size is 0.18 deg. which corresponds to 15m in the distance of 5km. FALCON-A has regular observations in these three years even in winter seasons. Examples of observation results are shown, in which precise structures and dynamics of cloud interior are revealed.
Active Phased Antenna Arrays Calibration Method Including Edge Effects and Mutual Coupling
Taguhi Chalumyan (LTCI, CNRS, Télécom ParisTech, Université Paris-Saclay, France); Olivier Maas (THALES Air Systems Business Line Surface Radar, France); Xavier Begaud (LTCI, Télécom ParisTech, Université Paris-Saclay, France); Bernard Huyart (TelecomParisTech, France)
A new calibration method of active phased array antennas is presented in this paper. This method can be applied to the antenna arrays of various sizes and various radiating element numbers. It takes into account the edge effects and mutual coupling. This method allows avoiding the degradations of the antenna radiation pattern caused by mismatch produced during a scanning and/or a weighting process. HFSS software is used to provide near-field electromagnetic numerical simulations. Matlab is used for far-field calculation from the near-field data; and also for the calculation of the illumination on the antenna surface by back-propagation of far-field data. The calibration process is performed by an optimization process by means of ADS software. An equivalent schematic is built in it in order to obtain desired radiation pattern corresponding to the illumination on the antenna surface. This method is applied to a concrete case in order to demonstrate its efficiency.
Feature Extraction Based on 2D Compressive Sensing for SAR Automatic Target Recognition
Baiyuan Ding and Gongjian Wen (National University of Defense Technology, P.R. China); Fen Ye (Huayin Ordnance test Center of China, P.R. China); Xiaohong Huang and Xiaoliang Yang (National University of Defense Technology, P.R. China)
This paper proposes a new feature extraction method for synthetic aperture radar (SAR) images with application to automatic target recognition (ATR). The original SAR image is first represented by a sparse image containing only a few dominant scattering centers (SCs). According to the theory of 2D compressive sensing (CS), a sparse image can be reconstructed from a low dimensional matrix with little distortion. Therefore, we use 2D random projection to extract features from the sparse image. The proposed method directly works on the 2D images thus avoiding the conversion of 2D matrices to vectors. Based on the extracted feature, the nearest neighbor classifier (NNC) is employed for target recognition. Experiments are conducted on the moving and stationary target acquisition and recognition (MSTAR) to evaluate the validity of the proposed method. Comparison with other methods demonstrates the superiority of the proposed method.
Design of an Equal Division Single-Band Filtering Power Divider Based on Ring Resonator Band-pass Filter
Zafar Bedar Khan and Huiling Zhao (Northwestern Polytechnical University, P.R. China)
In this paper a ring resonator (RR) based band pass filter (BPF) is integrated in the power divider for simultaneous filtering and equal division functions. The proposed co-axial feeding mechanism for the RR ensures the BPF response. Exploiting band-pass characteristics and matching the filter to 70.7 Ω, the RR BPF is integrated in place of the conventional quarter wave transformer in the power divider. In order to ensure good output isolation and return loss (RL), a 50Ω extended transmission line and a resistor is used. Experimental validation was carried out by fabricating the proposed filtering divider. The simulated and measured S-parameter responses were found in good agreement at the fundamental design frequency of 3 GHz and fractional bandwidth of 15%.
Mode-Matching Modeling of Low-Frequency Wireless Telemetry in Deep Oil Fields
Guilherme S. Rosa (Pontifical Catholic University of Rio de Janeiro, PUC-Rio, Brazil); Jose R Bergmann (PUC-Rio, Brazil); Fernando Teixeira (The Ohio State University, USA)
Wireless telemetry systems from the earth's surface to downhole antennas used in oil and gas exploration generally exploits the annulus between the casing and the tubing as a transmission media. This problem can be efficiently analyzed with a mode-matching technique (MMT), which only require modest computational resource to evaluate the propagation along the entire oil well. Prior MMT results have shown the potential of wireless telemetry systems in deep oil wells using extremely low frequencies. In this paper, we investigate the effects of the presence of a high-loss annulus region and the finite conductivity of metallic pipes on the expected system performance. We show that, for long distances, the fields become mostly confined around the external casing, thus enabling transmission over long well depths despite the high losses in the annular region.
Modeling the Impact of Solar Parks on VHF Aeronautical Communications
Helene Galiègue (ENAC, Université de Toulouse, France); Alexandre Chabory (ENAC, France)
The setting of photovoltaic power stations near aeronautical communication, navigation and surveillance (CNS) devices may cause scattering and multipath effects. For VHF radiocommunications, this may lead to a critical degradation of onboard/ground communications. This paper aims at proposing a fast computation of the impact of such solar parks on communication signals, based on the solar-panels bistatic radar cross section (RCS) and multipath calculation.
Comparisons of Discrete and Continuous Propagators for the Modelling of Low Tropospheric Propagation
Hang Zhou (Ecole National de l'Aviation Civile, France); Alexandre Chabory (ENAC, France); Rémi Douvenot (Ecole National de l'Aviation Civile, France)
For modelling the propagation of electromagnetic waves in the low troposphere, the discrete mixed Fourier method is classically used. It is based on a finite-difference approximation of the ground boundary condition. However, the propagator of the split-step Fourier method is derived from continuous equations. In this paper, we apply the finite-difference approximation to the propagation equation. A discrete operator is derived from these discrete equations. The continuous and discrete propagators are compared. The accuracy of these propagators is numerically analysed in free space and over an impedance ground. We show that the discrete propagator avoids some numerical instabilities.
Consideration on Incidence and Reflection Characteristics of Hydrated Soil for Landslides Prognostication Systems Using Electromagnetic Waves
Kohsei Kumahara, Kengo Nakajima and Futoshi Kuroki (National Institute of Technology, Kure College, Japan); Masanori Eguchi and Takeshi Yamakawa (Fuzzy Logic Systems Institute, Japan)
Recently, contactless landslides prognostication systems using light wave lasers and ultrasonic waves have been researched and developed, but they suffer from deterioration of detection accuracy due to environment resistance. To overcome such difficulty, electromagnetic waves have been focused on, and a system which can detect water contents in hydrated soil by electromagnetic waves has been investigated in this paper. As the first step, the measurement of the dielectric characteristics of the hydrated soil and the calculation of the incidence and reflection characteristics of the electromagnetic wave in the hydrated soil were performed as a function of the operating frequency. And thus, a possibility to prognosticate landslides was indicated by the reflection performance from the hydrated soil at medium frequency band.
Passively Coded Synthetic Aperture Interferometric Radiometer (CSAIR): Theory and Measurement Results
Ettien Lazare Kpré (Limoges University & XLIM Laboratory, France); Cyril Decroze (XLIM, France)
Based on the synthetic interferometric imaging technique (SAIR), a new microwave radiometer architecture is proposed in this paper to detect thermal noise sources with a passive coded measurement approach so called CSAIR. In this new system, a passive microwave device is used to intrinsically code and multiplex the antenna signals. This allows the reduction of the number of RF chains while keeping the same antenna array configuration needed in a conventional interferometric radiometers. The system principle is described and the signal processing required for the target brightness temperature rendering is also discussed. Simulation and measurement results show the effectiveness and the potential of the proposed system.
Radar Cross Section Measurement of Conformal Antenna Based on Microwave Imaging
Chufeng Hu (Northwestern Polytechnical University, P.R. China); Li Nanjing (Northwest Polytechnic University, P.R. China); Weijun Chen and Guo Shuxia (Northwestern Polytechnical University, P.R. China)
Radar cross section (RCS) of conformal antenna integrated into the aircraft surface cannot be measured by general RCS measurement method. A new method is presented in this paper in order to achieve accurate RCS of conformal antenna. RCS of conformal antenna is obtained by spatial spectral transforming and scaling of two-dimension (2-D) microwave imaging. Empirical results also show the proposed method is effective.
Main Circular Slot Effects on Impedance Matching and Radiation Patterns: Application in UWB Antennas
Mohamed Hayouni (Sup'Com, Tunisia); F. Choubani (SUP'COM, Tunisia); Tan-Hoa Vuong (LAPLACE-INPT, France); J. David (Enseeiht, France)
Parametric studies followed by experimental results of the impedance matching of a compact monopole patch antenna with an embedded half-guided wavelength circular slot, prove that a band-notching/bandwidth enhancement dual role can be achieved by shifting from a semicircular slot to small circular slot respectively by keeping the same inner radius. Moreover, measured radiation patterns in the H-plane are stably omnidirectional at 5.8 and 7.5 GHz. It is shown also that the cross-polarization in the same plane and at the same frequencies are not as low as single monopole due to some strong transverse currents around the small circular symmetric embedded slot. We noticed that there appears to be a close correspondence between the minimum of EФ and the maximum of Eθ electrical components.
Behavioral Model of Ionospheric Effects in HF Radars
Marie José Abi Akl (Université Pierre et Marie Curie & ONERA, France); Florent Jangal (Onera - The French Aerospace Lab, France); Muriel Darces and Marc Hélier (UPMC Univ Paris 6, France)
The sky and the surface wave radars can be impacted by the instabilities of the ionosphere while they perform continuous surveillance of far off areas. When long-term integration is performed, those instabilities are leading to an increased false alarm rate. This is the typical case when detecting slow targets. In this paper, we will discuss the case of a hybrid mode of detection. Two phenomena can then occur: the fluctuation of the reflection on the ionosphere and the backscattering by irregularities. We will introduce probabilistic models of the ionospheric effects assuming that only the phase path fluctuation has a meaning in the radar point of view. A model has been implemented and applied in the radar processing. The latter is compared to actual data acquired with our high frequency surface wave radar deployed in the south-east of France. The obtained results will be presented during the EuCAP 2017 conference.
Application of Doppler Radar for the Recognition of Hand Gestures Using Optimized Deep Convolutional Neural Networks
Youngwook Kim and Brian Toomajian (California State University, Fresno, USA)
We investigate the optimal structure of deep convolutional neural networks for classifying human hand gestures using Doppler radar. When hand motions are captured by Doppler radar, the unique micro-Doppler signatures can be observed in the spectrogram. If the signature is distinguishable by a classifier, then the hand gesture can be used for controlling electronics and as an input modality for a human-computer interface. To classify signatures in the spectrogram, we propose the use of a deep convolutional neural network (DCNN) as a classifier. DCNN is a powerful classifier that extracts features as well as class boundaries through a training process. We measured seven hand gestures performed in front of Doppler radar while generating spectrograms. To identify an optimal structure, we trained several DCNNs by changing hyperparameters, such as the number of filters. The classification accuracy obtained from the optimal DCNN structure was approximately 87%.

#### WG_03 Measurement EurAAP WG

WG Meetings & Workshops: Room 313/314
Chairs: Sergiy Pivnenko (Antenna Systems Solutions, Denmark), Manuel Sierra-Castañer (Universidad Politécnica de Madrid, Spain)

### Tuesday, March 21, 13:30 - 16:20

#### SWS_01: Advances in Commercial Electromagnetic Simulation Tools

WG Meetings & WorkShops: Room 315
Chairs: Marc Rütschlin (CST AG, United Kingdom (Great Britain)), Winfried Simon (IMST GmbH, Germany)

### Tuesday, March 21, 15:00 - 16:20

#### Inv_01 Invited Session 1

Room: Oral Sessions: Auditorium Bordeaux
Chairs: Luis Jofre (Universitat Politecnica de Catalunya, Spain), Andrea Neto (Delft University of Technology, The Netherlands)
15:00 Antenna Designs Based on Gap Waveguide Technology
Eva Rajo-Iglesias (University Carlos III of Madrid, Spain)
Gap waveguide technology is based on the control of wave propagation by using periodic structures. This technology, derived from the metamaterials and artificial surfaces background, has been employed during the last seven years to develop new antenna system components. The main advantage is the compromised low loss characteristic/low cost feature, provided by the possibility of using only metal and the non required electrical contact. Consequently, the technology has a lot of potential to be use in the millimeter wave frequency range. Along these years, classical antenna designs have been revisited using this technology as for instance slot arrays or leaky wave antennas but also other system components such as filters, diplexers or feed networks. A global overview of the technology, the different metasurfaces to be used and mainly the state of the art in terms of antenna designs making use of it will be presented in the talk.
15:40 Terahertz Science, Technology, and Applications
For more than last forty years, terahertz components and instruments have primarily been developed for space science applications in radio astronomy and planetary sciences. However, in recent years, terahertz waves are increasingly being used in commercial applications such as high speed communications, security imaging, autonomous landing and refueling of airplanes, and medicines. In spite of all these fascinating scientific and commercial potential, the terahertz frequency range (loosely defined as 300 GHz < ν < 10 THz) still remains one of the least utilized electromagnetic bands because of the unavailability of commercial source and sensor components, and sub-systems. Recent progress in CMOS technology as well as availability of InP HEMT based amplifiers in terahertz frequency band has caught the imagination of researchers for developing terahertz instruments for commercial applications as well. Rapid progress in multiple fronts, such as commercial software for component and device modeling, low-loss waveguide circuits and interconnect technologies, silicon micromachining for highly integrated and compact packaging, and submicron scale lithographic techniques, is making it an exciting time for terahertz engineers and scientists. In this presentation, an overview of the state of the terahertz technology will be presented. The talk will detail the science and other applications that specifically require technology at terahertz frequencies. The challenges of the future generation instruments, detectors, and antennas at these frequencies in addressing the needs for critical scientific and commercial applications will also be discussed. The research described herein was carried out at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA, under contract with National Aeronautics and Space Administration.

#### Inv_02 Invited Session 2

Room: Oral Sessions: Auditorium Havane
Chairs: Thomas Kürner (Technische Universität Braunschweig, Germany), Werner Wiesbeck (Karlsruhe Institute of Technology, Germany)
15:00 Towards a Channel Model for 5G
Sana Salous (Durham University, United Kingdom (Great Britain))
Future mobile radio systems are expected to use a variety of techniques and frequencies toward providing high data rates to the user. This has led to a concerted international effort towards characterizing the radio channel in the higher frequency bands particularly in the frequency range of 24-86 GHz following the World Radiocommunications Conference in November 2015 (WRC15). This talk gives an overview of radio propagation measurements in the UK towards achieving a channel model in these frequency bands and the international effort towards achieving such a model.
15:40 Human Body Imaging and Remote Vital Monitoring Using UWB Doppler Radar
Takuya Sakamoto (University of Hyogo & University of Hawaii at Manoa, Japan)
This talk introduces recent developments in the signal processing aspects of ultra-wideband (UWB) radar technology for measuring human bodies. Ultra-wideband radar has various applications, including measuring body shape and action types, and even remotely measuring vital signs such as respiration and heartbeat. This talk covers several advanced signal processing techniques, which are applicable to UWB radar data for retrieving information about the subject. Near-field radar imaging technology is currently used for body scanners at airports intended to detect concealed weapons. Our techniques enable us to generate high-quality radar images quickly, which is crucial for real-time applications. Another technique we have been developing is related to noncontact measurement of vital signs, which could be a breakthrough in the recent trend of health-conscious gadgets. Our signal processing helped us to achieve an unprecedented level of accuracy in the noncontact measurement of instantaneous heartbeat intervals using a multiple-input multiple-output UWB radar system.

#### WG_03 AMTA Europe Meeting

WG Meetings & Workshops: Room 313/314
Chairs: Sergiy Pivnenko (Antenna Systems Solutions, Denmark), Manuel Sierra-Castañer (Universidad Politécnica de Madrid, Spain)

### Tuesday, March 21, 16:50 - 18:30

#### Sp_A01 Frequency & Polarization Selective Surfaces

Space / Regular Session / Antennas
Room: Oral Sessions: Auditorium Bordeaux
Chairs: Andrea Neto (Delft University of Technology, The Netherlands), Min Zhou (TICRA, Denmark)
16:50 Broadband Multilayer Polarizer for Low-cost Ka-band Applications
Darwin Blanco and Ronan Sauleau (University of Rennes 1, France)
In this work we present a broadband multilayer polarizer. It is designed as an add-on device that could be integrated to any linearly-polarized antenna (without affecting its behaviour) to create circular polarization (CP). The achieved axial ratio (AR) is kept below 3 dB within a bandwidth of 14$\%$ ranging from 27.35GHz to 31.35GHz. All results are verified via full-wave simulations over an angular variation of $\pm$60 deg.
17:10 Co-Design of Frequency Selective Surface and Antenna Array with Low Angular Dependence
Cristina Yepes, Daniele Cavallo and Andrea Neto (Delft University of Technology, The Netherlands); Erio Gandini (TNO, The Netherlands); Stefania Monni and Frank van Vliet (TNO Defence Security and Safety, The Netherlands)
We present the design of a multi-layer frequency selective surface (FSS) composed of subwavelength elements, with large harmonic rejection bandwidth. The FSS design is based on an equivalent circuit model, where the inter-layer interaction is only described with a single transmission line representing the fundamental Floquet wave. To ensure the accuracy of this model, we enforce the FSS period to be comparable to the inter-layer distance. The FSS comprises five metal layers and has an overall height of one sixth of the wavelength at the central frequency of operation. The FSS simulated response exhibits good stability over a wide conical incidence range, up to 45 degrees. The FSS is then combined with a wide-scanning connected array of slots to implement an antenna element for phased array applications, with integrated filtering properties.
17:30 Design of Aperiodic Frequency Selective Surfaces for Compact Quasi-Optical Networks
Min Zhou, Stig Sørensen and Niels Vesterdal (TICRA, Denmark); Raymond Dickie (Queens University Belfast, United Kingdom (Great Britain)); Paul Baine and John Montgomery (Queen's University Belfast, United Kingdom (Great Britain)); Robert Cahill (Queens University Belfast, United Kingdom (Great Britain)); Manju Henry (Rutherford Appleton Laboratory, United Kingdom (Great Britain)); Peter Huggard (STFC Rutherford Appleton Laboratory, United Kingdom (Great Britain)); Giovanni Toso (European Space Agency, The Netherlands)
The design of an aperiodic frequency selective surface (FSS) for compact quasi-optical networks is presented in this paper. Using a newly developed Physical Optics (PO) method in conjunction with a direct optimisation approach where all elements are simultaneously optimised, an FSS with an aperiodic element layout operating in several discrete bands over the frequency range 23-230 GHz has been designed. The design procedure and a comparison with an existing periodic FSS designed to meet the same specifications are provided. This comparison indicates that enhanced performance can be obtained using an aperiodic FSS compared to a periodic FSS.
17:50 Systematic Design of a Class of Wideband Circular Polarizers Using Dispersion Engineering
Francesco Foglia Manzillo (CEA-LETI, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Ronan Sauleau (University of Rennes 1, France); Anthony Grbic (University of Michigan, Ann Arbor, USA)
A novel topology and a systematic procedure for the design of wideband linear-to-circular polarization converters are presented. The proposed configuration consists of three anisotropic inductive sheets, separated by two dielectric spacers. The dispersion curves for the two polarizations are engineered to achieve a broadband, linear phase response. The design procedure maximizes the differential phase bandwidth. The circuit parameters of the design are derived without any optimization. Fractional bandwidths larger than 48.5%, for incident angles up to 30°, are achieved. A printed circuit board (PCB) realization is discussed in order to numerically validate the proposed approach.
18:10 Study of Factors Influencing Performance of Substrate Backed FSS for Millimeter Wave Atmopsheric Remote Sensing
Jayaprakash Poojali (Indian Institute of Technology Madras, India); Shaumik Ray and Bala Pesala (CSIR CEERI, India); Krishnamoorthy Chitti and Kavitha Arunachalam (Indian Institute of Technology Madras, India)
A Frequency Selective Surface on 175 µm thick quartz with gold trace and unit cell size of 728 µm x 728 µm was proposed in our earlier work for isolating three bands in 50 GHz - 200 GHz range for passive remote sensing. In this work, we present the factors influencing the performance of substrate backed FSS on frequency de-multiplexing. 3D numerical modeling is used to investigate the influence of the thickness of the gold trace and fabrication tolerance on FSS transmission. Scanning electron microscopy (SEM) images confirmed a uniform gold deposition (1.85 µm) across the 35 mm x 35 mm FSS structures with ±2 µm fabrication tolerance on the unit cell dimensions. Continuous wave terahertz measurements of the fabricated samples showed at least 10 dB and 0.5 dB transmission losses in the reflection and transmission bands respectively for TE polarization and varying angle of incidence (0° to 45°).

#### CS11 Current Challenges in Low Frequency Antenna System Verification

Space / Convened Session / Measurements
Room: Oral Sessions: Auditorium Havane
Chairs: Benedetta Fiorelli (European Space Agency, The Netherlands), Giuseppe Virone (Consiglio Nazionale delle Ricerche, Italy)
16:50 RF Verification of RIME Antenna to Be Flown on JUICE Spacecraft
Uwe Kummer, Christian Imhof and Michael Moll (Airbus DS GmbH, Germany); Dirk Plettemeier (Dresden University of Technology, Germany)
RIME (Radar for Icy Moons Exploration) is a radar sounder for the JUICE (Jupiter ICy moons Explorer) mission. The instrument shall probe the inner structures of the icy crust of the moons Callisto Europa and Ganymede up to a depth of 9 km. For ensuring a sufficient penetration depth the instrument is operated at the frequency range 7.5 - 10.5 MHz. The instrument is equipped with a lambda/2 dipole with decentral feeding. Its RF characteristics are strongly affected by the electromagnetic coupling to the S/C surfaces and also the RF verification is strongly constrained by any coupling to the environment. The presentation outlines the envisaged test approach for verifying impedance, efficiency and selected directions of the antenna pattern first for the isolated antenna and thereafter for an antenna mounted on a S/C mockup.
17:10 Deployable VHF Band Log-periodic Dipole Array: Challenges in Verification
Tao Huang and Vincent Fraux (Oxford Space Systems, United Kingdom (Great Britain))
This paper presents challenges in verifying the design of a space deployable VHF band orthogonal log-periodic dipole array (LPDA). Due to the construction nature of the antenna, operating frequency band, physical dimensions and 1g environment on ground there are a number of challenges in antenna RF measurements and verifications. These are discussed and presented in this paper.
17:30 Experimental Characterization of a Dual-Polarized Direction Finding Array for VHF-UHF Frequency Bands
Luca Scorrano (Elettronica S.p.A., Italy); Libero Dinoi (Elettronica SpA, Italy)
In this contribution, we present the experimental characterization procedure of a compact DF array for the 70- 1300 MHz frequency band, solving critical antenna coupling issues. It comprises four different specialized subarrays enabling both dual-polarization operation and a maximum error in the estimate of the Angle of Arrival (AoA) well below 2° RMS in the most of the frequency and angular interval of interest.
17:50 Measurements of Low Gain Antennas at VHF Frequencies for Space-Based AIS Applications
Andrea Giacomini (Microwave Vision Italy, Italy); Vincenzo Schirosi (MICROWAVE VISION ITALY, Italy); Francesco Saccardi and Francesca Rossi (Microwave Vision Italy, Italy); Nelson Fonseca and Peter de Maagt (European Space Agency, The Netherlands); Lars Foged (Microwave Vision Italy, Italy)
Measurement of the radiation properties of low gain antennas at VHF frequency is in many cases a challenging task. Measurements performed in shielded anechoic chambers are usually preferred to outdoor ranges because they are not subject to the electromagnetic pollution and less affected by the scattering of the environment. However, different source of errors, such as truncation of the scanning surface and the presence of echoes caused by a poor reflectivity of the anechoic chamber, could affect the measurement results. In such cases, advanced post-processing techniques must be involved. In this paper, the results of two Engineering Models of a low gain VHF space antenna are reported. The first one has been tested in a multi-probe automotive hemispherical range and applying an advanced processing, in order to mitigate the truncation errors. The second has been measured in a spherical multi-probe system with smaller truncated area applying the standard data processing.
18:10 UAV-based Antenna Measurements: Scan Strategies
Fabio Paonessa (IEIIT - CNR, Italy); Giuseppe Virone (Consiglio Nazionale delle Ricerche, Italy); Pietro Bolli (Osservatorio Astrofisico di Arcetri, Italy); Andrea Lingua (Politecnico di Torino, Italy)
In the recent years, the authors developed a system for the characterization of the radiation pattern of VHF and UHF antennas by means of a test-source mounted on a micro Unmanned Aerial Vehicle (UAV). So far, the adopted scan strategies typically consisted of two orthogonal straight paths at constant height from ground to obtain E- or H-plane cuts. In this paper, more complex scan strategies are presented to perform two-dimensional pattern measurements over planar and curved surfaces.

#### W_A04 Mm-Wave Antennas for Wireless Networks

Wireless Networks / Regular Session / Antennas
Oral Sessions: Room 341
Chairs: Carlos Del-Río (Universidad Publica de Navarra & Institute of Smart Cities, Spain), Ingmar Kallfass (University of Stuttgart, Germany)
16:50 Experience in Developing LTCC Technologies for mm-Wave Antennas
Yevhen Yashchyshyn (Warsaw University of Technology & Institute of Radioelectronics, Poland); Paweł R. Bajurko, Przemysław Piasecki, Piotr Włodarczyk, Konrad Godziszewski and Jakub Sobolewski (Warsaw University of Technology, Poland); Beata Synkiewicz and Jan Kulawik (Institute of Electron Technology, Poland)
This paper presents the experience in designing LTCC antennas operated in D-band. A few examined structures are presented and their electrical parameters dependencies on LTCC technology limitations are shown. There are two main points: the first one is related to the quality of multi-layered structures and the second one to the properties of metalization, which has a big influence on electrical parameters of designed structures. Effect of material shrinkage is also investigated. Additionally, possibility of creating air cavities to lower the effective permittivity of substrate material is considered.
17:10 A High Gain Steerable Millimeter-Wave Antenna Array for 5G Smartphone Applications
Manoj Stanley and Yi Huang (University of Liverpool, United Kingdom (Great Britain)); Tian Hong Loh (UK, National Physical Laboratory, United Kingdom (Great Britain)); Qian Xu (University of Liverpool, United Kingdom (Great Britain)); Hanyang Wang (Huawei Technologies, United Kingdom (Great Britain)); Hai Zhou (Huawei Technology (UK), United Kingdom (Great Britain))
In this paper, a phased array antenna is designed at millimeter-wave frequency bands for future 5G based smartphone applications. The proposed antenna is a novel open slot-PIFA antenna made on a low-cost FR4 board. The antenna array covers a frequency range of 26-32 GHz with a bandwidth of 6 GHz. The antenna exhibits a very good radiation pattern when integrated with the mobile phone chassis. The 8 - element antenna array exhibits a maximum gain around 13 dBi. The pattern can be steered by varying the phase shift at each antenna element.
17:30 Low-Cost Circularly Polarized Spiral Antenna Array for 60 GHz Applications
Qian Zhu, Kung Bo Ng and Chi Hou Chan (City University of Hong Kong, Hong Kong)
A 4 × 4 circularly polarized antenna array with a substrate integrated waveguide feed network is proposed in this paper. The array is fabricated using low-cost printed-circuit-board and plated-through-hole technologies. The wideband single element is a modified spiral antenna with unequal arm lengths. The measured -10-dB reflection coefficient and 3.2-dB axial ratio bandwidths are 15.7% and 15%, respectively, while the measured gain at 60 GHz is 18.7 dBic.
17:50 Surface-Bulk Micromachined On-Chip Monopole Antenna for 77 GHz Automotive Radar Applications
Hossam Helaly, Ezzeldin Soliman and Mohamed Serry (The American University in Cairo, Egypt)
This paper presents a micormachined quarterwavelength monopole antenna operating at the millimeterwave band for automotive radar application, specifically a77GHz. The antenna will be realized using surface micromachining on a low resistive thick silicon substrate and fed by coplanar waveguide. Bulk micromachining is used to etch silicon underneath the antenna in order to reduce the Ohmic losses in the substrate. The proposed antenna is analyzed and optimized using CST. The obtained bandwidth, gain, directivity, and efficiency are 40.25%, 3.55 dBi, 5.49 dBi,and 64%, respectively.
18:10 Dual-band Slotted Waveguide Antenna Array for Adaptive Mm-wave 5G Networks
Igor da Costa and Arismar Cerqueira S. Jr. (INATEL, Brazil); Danilo Spadoti (Universidade Federal de Itajubá - UNIFEI, Brazil)
This paper describes the design, simulation and measurement of a dual-band slotted waveguide antenna array for adaptive 5G networks, operating in the millimeter wave frequency range. Its structure is composed by two groups of slots milled onto the opposite faces of a rectangular waveguide, enabling antenna operation over two different frequency bands, namely 28 and 38 GHz. Measured and numerical results, obtained using ANSYS HFSS, demonstrate two bandwidths of approximately 26.36% and 9.78% for 28 GHz and 38 GHz, respectively. The antenna gain varies from 12.6 dBi for the lower frequency band to 15.6dBi for the higher one.

#### C_P05 Time-Varying Radio Channels

Cellular Communications / Regular Session / Propagation
Oral Sessions: Room 342A
Chairs: Iñigo Cuiñas (University of Vigo, Spain), Dragan I. Olcan (University of Belgrade, Serbia)
16:50 The Excess Attenuation of Propagating Wave in the Presence of Human Crowds
Jovana Perovic (School of Electrical Engineering University of Belgrade, Serbia); Dragan I. Olcan and Branko Kolundzija (University of Belgrade, Serbia)
We present a formula that can approximate the excess attenuation of electric field of electromagnetic wave propagating in the presence of human crowds. The formula is tested on results obtained from full wave simulations of 2D and 3D stochastic models of human crowds. The electric field is either vertically or horizontally polarized at frequencies 900 MHz and 1800 MHz. We use two stage nonlinear optimizations to find the parameters of the formula.
17:10 Channel Modeling for Kiosk Downloading Communication System at 300 GHz
Danping He (Beijing Jiaotong University, P.R. China); Ke Guan (Beijing Jiaotong University, P.R. China & Technische Universität Braunschweig, Germany); Bo Ai (Beijing Jiaotong University & State Key Lab of Rail Traffic Control and Safety, P.R. China); Alexander Fricke (Technische Universität Braunschweig, Germany); Ruisi He and Zhangdui Zhong (Beijing Jiaotong University, P.R. China); Akifumi Kasamatsu (National Institute of Imformation and Communications Technology (NICT), Japan); Iwao Hosako (National Institute of Information & Communications Technology, Japan); Thomas Kürner (Technische Universität Braunschweig, Germany)
In the race towards ultra-high-data-rate wireless communication systems, terahertz (THz) band communication is envisioned as a key wireless technology to satisfy this demand and overcome the spectrum scarcity of current wireless systems. As more and more users prefer to accessing digital information with mobile device anytime and anywhere, the close proximity data transfer are needed. In this paper, propagation channel at 300 GHz is studied for Kiosk downloading application. Key parameters of the propagation channel are extracted and modeled based on measurements and calibrated ray tracing simulations. The developed channel model allows for fast generation of channel transfer function. Moreover, the modeling results are evaluated in terms of Rician K-factor and root mean square delay spread. The absolute mean errors of these two metrics are 0.9 dB and 0.07 nanoseconds, respectively. The validated channel model can be used for close proximity communication system design at THz frequencies.
17:30 Time-variant Channel Characteristics at 20 GHz Band in Urban Street Canyon Environment
This paper presents the time-variant channel characteristics at 20 GHz band for line of sight (LoS) scenario in urban street canyon environment. A measurement campaign was conducted using a channel sounder for 20 GHz band with a 50-MHz-bandwidth. A uniform planar array (UPA) in form of 16-by-16 matrix was also used for the receiver side in order to measure time-variant power delay profiles, azimuth/elevation angle of departures (AoD/EoD). The measured results show that the correlation values of standard deviation (std) of delay spreads (DS), azimuth spread of departure angles (ASD), elevation spread of departure angles (ESD) and transmission distances are 0.78, 0.22, 0.78, respectively. Moreover, the correlation value of std and average of DS is high about 0.98. One the other hand, the correlation value of std and average of ASD, and the correlation value of std and average of ESD are low about 0.04 and 0.55, respectively.
17:50 Identifying Radio Waves Direction of Arrival by Doppler Deviation Along Linear Paths At 5.8 GHz
Iñigo Cuiñas (University of Vigo, Spain); Manuel García Sánchez (Universidade de Vigo, Spain)
This contribution reports the results of a large broad band measurement campaign on the frequency response of radio channels at 5.8 GHz band. Up to five scenarios, in both line of sight and obstructed line of sight, configure the testbed of this work. After gathering data along linear paths, Doppler effect principles allow the estimation of the angle of arrival of any multipath contribution. The analysis of this processing application occupies most of the contribution, which also provides the possibilities and limitations of using such a method to detect the radio sources in a multipath environment.
18:10 Experimental Measurements and Channel Modeling for Wireless Communication Networks in Underground Mine Environments
Alok Ranjan (National Institute Of Technology, Rourkela, India); Prasant Misra (TATA Consultancy Services, India); H Sahu (NIT Rourkela, India)
Compared to rail/road tunnel the characteristics of electromagnetic (EM) wave propagation in underground mine tunnel is significantly different. For reliable operation of wireless communication system in underground mine environment; an understanding of radio signal behavior in such confined space is crucial. This paper discusses the experimental findings carried out in an operational underground mine and further proposed a modified multimode channel model for wireless communication networks in underground mine environments. The proposed channel model is validated with the experimental measurements carried out in both circular and rectangular coal mine tunnels. Based on the proposed channel model, we further analyzed the radio signal behavior considering antenna position and size of the tunnel. Our results are useful to understand the wireless signal propagation characteristics in underground mines, hence may be useful to design reliable and robust communication devices for such high-stress environments.

#### CS32 OPTIC BIOEM and other approaches for electropulsation in medicine and biology

Biomedical / Convened Session / Propagation
Oral Sessions: Room 342B
Chairs: Micaela Liberti (ICEmB at "Sapienza" University of Rome, Italy), Caterina Merla (ENEA SSPT Division of Health Protection Technologies, Italy)
16:50 Microchambers and Devices for Cells Exposure: From the Design to Applications
Francesca Apollonio (University Sapienza of Rome, Italy); Maura Casciola (Frank Reidy Research Center for Bioelectrics Old Dominion University, USA); Agnese Denzi (IIT, Italy); Micaela Liberti (ICEmB at "Sapienza" University of Rome, Italy); Paolo Marracino (La Sapienza University, Rome, Italy); Caterina Merla (ENEA SSPT Division of Health Protection Technologies, Italy); Alessandra Paffi (Sapienza University of Rome, Italy)
In the last decades, the advances in the micro and nano-fabrication techniques have led to the development of microdevices that have improved the possibility of analysis at cell level. These devices can be used in different applications: cell detection and identification, manipulation, cell treatments, but in particular they seem extremely promising for nanosecond pulses applications, where the requisite of broadband matching becomes highly demanding. In this paper after a brief review of applicators for nanosecond pulses, a multi step procedure for a good design of microdevices is fixed and an example of microchamber design is given.
17:10 Detection of Effects of External Electric Pulses on Properties of Biological Membrane with Electrical and Optical Diagnostics
Aude Silve (Institute for Pulsed Power and Microwave Technology, Karlsruhe Institute of Technology, Germany); Lars Wegner and Wolfgang Frey (Institute for Pulsed Power and Microwave Technology, KIT, Germany)
Electric pulses can modify properties of cells membrane and make it permeable to molecules that normally are non-permeant. One way to study this effect is therefore to observe transport of molecules across the membrane. However, the outcome of such experiments not only depends on damages induced to the membrane but also on properties of the transported molecules which are investigated and on the transport mechanisms which are involved. Some other approaches, are however available and can provide more straight forward information on the state of a membrane. Electrical diagnostics, such as bioimpedance or patch-clamp, can provide direct information on the modification of the conductance of the cells membrane. Additionally, some optical diagnostics such as measurement of transmembrane voltage using voltage sensitive dyes can also be used to study modification of membrane conductance induced by pulsed electric fields. The benefits and drawbacks of each approaches will be discussed.
17:30 Response of Mammalian Cells to Non-thermal Intense Narrowband Pulsed Electric Fields
Sunao Katsuki (Kumamoto University & Institute of Pulsed Power Science, Japan); Yulan Li, Daiki Miyakawa, Ryo Yamada, Nobuaki Onishi and Soowon Lim (Kumamoto University, Japan)
This paper describes the biological effect of intense pulse electric field from the frequency point of view. 10 μs long sinusoidal electric fields with a frequency range between 0.1 and 100 MHz and field strengths of up to 10 kilovolt per cm were applied to HeLa or HeLa S3 cells, which were subsequently analyzed in terms of the morphology and the Ca2+ response. Our experiment shows that the possibility to physically activate membrane proteins without significant defects of the plasma membrane.
17:50 Perfused Organ Model Development and Evaluation for Irreversible Electroporation Investigations
Suyashree Bhonsle and Mohammad Bonakdar (Virginia Tech, USA); S Nahum Goldberg (Hadassah Medical Centre, Hebrew University, Israel & Beth Israel Deaconess Medical Center, USA); Rafael Davalos (Virginia Tech, USA); Robert Neal, II (Angiodynamics, USA)
Irreversible electroporation (IRE) is a technique to kill cells by delivering a series of short-duration, high voltage square wave electric pulses into tissue to alter the native cellular transmembrane potential, creating irrecoverable nanoscale defects in the cell membrane. IRE protocols constrain Joule heating below temperatures that cause coagulation of extracellular proteins, and consequently spare critical structures that contraindicate other thermal-based therapies. Tissue-level characterization and optimization of IRE treatment conventionally requires costly and logistically complex in vivo experiments, since affected zones cannot be visualized in expired ex vivo tissue. This has limited IRE protocol evolution. Here, an alternate method using active perfusion of freshly harvested organs with an appropriate viability stain is described, and offers an approach to visualize IRE-affected tissue. The lesions were validated against protocol-matched in vivo trials. This offers an approach to cheaply expedite IRE development, permitting faster protocol and device optimization, ultimately offering better clinical outcomes.
18:10 Diversity of Monopolar and Bipolar Nanosecond Pulsed Electric Signals on the Metallo-Enzyme Superoxide Dismutase (SOD), a Modelling Approach
Elena della Valle (University Sapienza of Rome, Italy); Paolo Marracino (Sapienza University of Rome, France); Olga Pakhomova (Frank Reidy Research Center for Bioelectrics Old Dominion University, USA); Micaela Liberti (ICEmB at "Sapienza" University of Rome, Italy); Francesca Apollonio (University Sapienza of Rome, Italy)
Recent papers showed that when dealing with nanosecond pulsed electric fields (nsPEFs), bipolar pulses proved far less effective at membrane permeabilization and at cell killing than monopolar ones, contrary to what happens in the microsecond range. The mechanism at the basis of such selective response of cells is not fully elucidated. One hypothesis worthwhile to test could be a direct action of nsPEFs on intracellular enzyme reactions. The goal of this study is to investigate possible enzyme response due to the application of nsPEF monopolar and bipolar of intensity of 108 V/m and duration of 100 ns on the superoxide dismutase (SOD,Cu-Zn) enzyme, by means of a molecular dynamics (MD) modelling approach.

#### CS47 THz Antennas and Subsystems for High Data Rate Communication Links

High Data-rate Transfer / Convened Session / Antennas
Oral Sessions: Room 343
Chairs: Yi Huang (University of Liverpool, United Kingdom (Great Britain)), Daniel Segovia-Vargas (Universidad Carlos III de Madrid, Spain)
16:50 High Data-Rate Communication Link at 240 GHz with On-Chip Antenna-Integrated Transmitter and Receiver Modules in SiGe HBT Technology
Janusz Grzyb, Pedro Rodriguez Vazquez, Neelanjan Sarmah and Wolfgang Wolfgang Förster (University of Wuppertal, Germany); Bernd Heinemann (IHP, Germany); Ullrich Pfeiffer (University of Wuppertal, Germany)
This paper reports on the development and experimental characterization of a high data-rate communication link at 240GHz with highly-integrated direct-conversion quadrature transmitter and receiver modules implemented in 130nm SiGe HBT technology with ft/fmax of 350/550 GHz. Both modules employ a low-cost chip-on-board packaging scheme with single-chip TX and RX front-end circuits accommodating wideband silicon lens-integrated wire ring on-chip antennas. The key highlights of the developed hardware are its high RF and IF operation bandwidths available from the printed-circuit board-level. With the preliminary wireless transmission tests, a 20Gbps and a 24Gbps transmission speed with an EVM of 24% was demonstrated for BPSK and QPSK modulation schemes at a distance of 90cm with no channel equalization applied. For a 10Gbps BPSK, an error-free communication link could be established.
17:10 Design of Electronic Subsystems for a 300 GHz Wireless Communication System
Jose M. Perez (Universidad Publica de Navarra, Spain); Iñigo Ederra (Universidad Pública de Navarra, Spain); Ramon Gonzalo (Public University of Navarra, Spain)
Recently, there has been an increasing interest in the THz gap due to the attractive applications that can be developed. Among these applications, high data rates communication system links get an important relevance due to the potential high bandwidth that can be obtained. In this paper, a frequency tripler and a fourth harmonic mixer for a wireless communication link at 300 GHz has been designed. Conversion Loss (CL) of the tripler is around 15 dB for 65 GHz bandwidth in which the best value is 12 dB for 318 GHz. For the fourth harmonic mixer, the CL obtained is around 18 dB within 41 GHz bandwidth. The best value is 10.2 dB for 301 GHz.
17:30 High-Power Terahertz Emitter for a Communication Link: The Chessboard Array
Alejandro Rivera-Lavado, Kerlos Atia-Abdalmalak and Gabriel Santamaria-Botello (Universidad Carlos III de Madrid, Spain); David González-Ovejero (Centre National de la Recherche Scientifique - CNRS, France); Guillermo Carpintero and Daniel Segovia-Vargas (Universidad Carlos III de Madrid, Spain); Ivan Camara-Mayorga (Max Planck Institute fur Radioastronomy, Germany); Luis-Enrique Garcia-Muñoz (University Carlos III of Madrid, Spain)
This manuscript proposes a high-power terahertz source that consists on a large amount of coherently driven photomixing THz sources. Each element is placed in the gap of a bow tie antenna. The resulting array defines a chessboard-like layout which maximize the density of devices. This novel concept is validated through full-wave simulations. Experimental considerations are also provided for a prototype manufactured for the 1550 nm window. Measured power level will be shown at the conference.
17:50 Design of Graphene-based Plasmonic Nano-antenna Arrays in the Presence of Mutual Coupling
Luke Zakrajsek and Erik Einarsson (University at Buffalo, USA); Ngwe Thawdar (AFRL); Michael Michael Medley (AFRL, USA); Josep M Jornet (University at Buffalo, USA)
Graphene-based plasmonic nano-antennas are envisioned as the enabling component for communication in the Terahertz (THz) band (0.1-10THz). Despite their efficiency and due to their size, the total radiation power is expectedly very low. To overcome this limitation, plasmonic nano-antenna arrays are proposed. In this paper, by using analytical models backed by numerical simulations, the performance of such arrays are analyzed while taking into account mutual coupling effects. It is shown that a nano-array can provide significant gain in relation to only a single nano-antenna while still occupying a compact footprint. The results in this paper serve as a building block towards future THz communication systems.
18:10 A THz Impulse Communications System
Elliott Brown (Wright State University, USA)
THz impulse communications is a new system concept based on an imaging radar that we have been developing for biomedical imaging applications the past ten years. Its hybrid architecture combines the high-peak-power and spread-spectrum of photoconductive-switch transmitters with the high-responsivity and broad-bandwidth (RF and video) of Schottky-rectifier receivers. The data is impressed by simple on-off keying of the transmitter utilizing the very stable repetition frequency of the fiber mode-locked laser (MLL) that drives the PC switch.

#### CS18 Glide Symmetry Surfaces for mm and Sub-mm Lens Antennas

Future Applications / Convened Session / Antennas
Oral Sessions: Room 351
Chairs: Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden), Krishnaswamy Sankaran (ETH Zurich & IIT Bombay, Switzerland)
16:50 Glide-Symmetric Metasurfaces: Theory, Simulation and Practice
Oscar Quevedo-Teruel, Mahsa Ebrahimpouri and Fatemeh Ghasemifard (KTH Royal Institute of Technology, Sweden); Malcolm Ng Mou Kehn (National Chiao Tung University, Taiwan); Rhiannon C Mitchell-Thomas (University of Exeter, United Kingdom (Great Britain)); Anthony Grbic (University of Michigan, Ann Arbor, USA); Zvonimir Sipus (University of Zagreb, Croatia); Eva Rajo-Iglesias (University Carlos III of Madrid, Spain); Guido Valerio (Sorbonne Universités UPMC, France)
In this paper, we summarize the recent results in electromagnetic glide-symmetric structures. A periodic structure is glide-symmetric when its lattice is created by a periodic mirroring and translation. These structures were of the interest to the microwave and antenna community during the '60s for one-dimensional periodicities. Recently, research on metasurfaces has revived the study of glide-symmetric structures due to their exceptional qualities in terms of low dispersion and rejected bands. Two-dimensional glide-symmetric metasurfaces find applications in lens antennas and gap waveguide technology.
17:10 Floquet-Mode Analysis of Glide-Symmetric Metasurfaces
Zvonimir Sipus (University of Zagreb, Croatia); Guido Valerio (Sorbonne Universités UPMC, France); Anthony Grbic (University of Michigan, Ann Arbor, USA)
In this paper, the analysis method for analyzing metasurface parallel-plate waveguides with glide symmetry is presented. The analysis method is based on Floquet-mode representation of the EM field inside the parallel-plate, and on matching it with the EM field at the waveguide opening. By this, a characteristic equation for the propagation constant of the waveguide mode is derived. The analysis method is tested by comparing the calculated propagation constant with the results obtained by a general electromagnetic solver.
17:30 High Index Metasurfaces for Graded Lenses Using Glide Symmetry
Rhiannon C Mitchell-Thomas, John Sambles and Alastair Hibbins (University of Exeter, United Kingdom (Great Britain))
A metasurface which has glide symmetry in two orthogonal directions is given here as the building block for the design of surface wave lenses. This metasurface is shown to have reduced frequency dispersion when compared to a similar structure with reflection symmetry only. This work has the potential to create graded index lenses, with a high mode-index contrast, for use in surface wave antenna applications.
17:50 Design of High Directivity Slot Arrays in the Millimeter-Wave Range Based on Groove Gap Waveguide Implemented with a Glide-Symmetric Holey Structure
Eva Rajo-Iglesias (University Carlos III of Madrid, Spain); Astrid Algaba Brazález (Ericsson Research, Ericsson AB, Sweden)
The use of gap waveguide technology is increasing continuously. In this work we present the first studies on the use of a new type of periodic structure to create the desired stop band and its application to design array antennas. The new unit cell belongs to the known as glide-symmetric structures and has a very simplified manufacturing. The latter is due to the larger periodicity of the structure when compared to the classical pins but also because manufacturing holes is always easier than making pins.
18:10 All-metal Ku-band Luneburg Lens Antenna Based on Variable Parallel Plate Spacing Fakir Bed of Nails
Cheikh Diallo (IETR & Université de Rennes 1, France); Etienne Girard (Thales Alenia Space, France); Hervé Legay (Thalès Alenia Space, France); Ronan Sauleau (University of Rennes 1, France)
This paper presents an all-metal parallel plate waveguide (PPW) Luneburg lens designed using an array of subwavelength Fakir bed of nails unit-cells. Variation of the metal post height and PPW-spacing modulates the effective refractive index. The lens operates in the Ku-band of frequencies, with more than 40\% bandwidth, in a quasi-TEM mode. Broadband and low loss, with high directivity and wide field-of-view, this antenna could be an excellent candidate as a lens-like beamformer for multiple beams satellite communication applications.

#### R_P01 Radar Imaging

Radars / Regular Session / Propagation
Oral Sessions: Room 352A
Chairs: Carey Rappaport (Northeastern University, USA), Okan Yurduseven (Duke University, USA)
16:50 A Null Steering Method for Detecting Buried Objects with Forward-Looking GPR
Yukinori Fuse and Masoud Rostami (Northeastern University, USA); Borja Gonzalez-Valdes (University of Vigo, Spain); Carey Rappaport (Northeastern University, USA)
A null steering method for Forward-Looking Ground Penetrating Radar (FLGPR) is presented. The radar consists of two arrays (one at L-band and one at X-band) of wideband horns that form synthetic apertures at the vehicle advanced. The null steering method is applied to the SAR vertical view (intensity vs. range and height) image to compensate for the lack of vertical image resolution and help determine if a scatterer is above the ground or buried. First, a target point is selected in the original SAR image, then a null for point spread function (PSF) is calculated for that point. The null PSF is applied to field data to indicate the position of the scatterer. This method is tested with a full-wave scattered field synthetically generated by FDFD, and with field measurement data.
17:10 Optimization of Frequency-Diverse Antennas for Computational Imaging at Microwave Frequencies
Okan Yurduseven and Jonah Gollub (Duke University, USA); Thomas Fromenteze (Duke University, France); Daniel Marks and David Smith (Duke University, USA)
Frequency-diverse imaging is an all-electronic method, capable of sampling the scene to be imaged without the need for a mechanical scan or active circuit components. In order to optimize the imaging characteristics, such as imaging resolution and fidelity of the reconstructed images, the antennas used within this scheme need to be optimized. It is demonstrated that using a Mills-Cross iris distribution, superior sampling of the Fourier components (wide support extent and minimum sampling redundancy) can be achieved. Using the optimized antennas, an experimental imaging system is built, reconstructing a good quality image of a cross-shaped target in less than 0.1 seconds.
17:30 Single-Frequency Near-Field MIMO Imaging
Thomas Fromenteze (Duke University, France); Michael Boyarsky, Jonah Gollub and Timothy Sleasman (Duke University, USA); Mohammadreza Imani (University of Michigan, USA); David Smith (Duke University, USA)
A near-field radar imaging technique is presented based on single-frequency measurements from a multiple-input multiple-output (MIMO) array. Such arrays are able to fully sample the $k$-space of a region of interest. Advantageously, both range and cross-range information can be reconstructed, in contrast to conventional single-input multiple-output systems which require wideband frequency illumination. A theory of single frequency MIMO imaging is developed and studied through numerical modeling and experimental validation.
17:50 A New Regularization Method for Radar Cross Section Imaging
Thomas Benoudiba-Campanini (Université de Bordeaux & CEA CESTA & IMS Bordeaux, France); Pierre Minvielle (CEA CESTA, France); Pierre Massaloux (CESTA, France); Jean-François Giovannelli (IMS, UMR CNRS 52 18, Université Bordeaux 1, France)
RCS analysis is the study of the scattering behavior of an object. The objective is to determine the main scatterers from measurements of the backscattered electric field. It is generally achieved by Radar Cross Section imaging. This leads to an ill-posed inverse problem because the system to solve is underdetermined. It is then necessary to regularize the problem by adding prior information. In this paper, a new constrained and sparse regularization method for Radar Cross Section imaging is proposed. It is based on the finite spatial electromagnetic extension of the target and its expected small number of scatterers. A least squares criterion with a L1 penalty and support constraints is developed. It is minimized by an efficient algorithm resting on an ADMM. The application to real scattered measurements is very promising, with a limited computation time. Compared to the conventional approach, the image resolution is drastically increased.
18:10 Electromagnetic Imaging of Wave Impenetrable Objects
Xiuzhu Ye (Beihang University, P.R. China)
This paper proposed a volume pixel subspace based optimization method (SOM), to solve the electromagnetic imaging problem of the wave impenetrable objects/perfect electric conductor (PEC). In this proposed method, the PEC objects are approximated by highly lossy dielectric scatterers with pure imaginary permittivity and thus volume pixel SOM is successfully employed. There is no prior information such as the number and locations of scatterers required in the inversion. Synthetic data as well as experimental data are both employed to test the validity of the method. The surface pixel SOM is also used to compare with this volume pixel SOM, showing that the nonlinearity of volume pixel SOM is reduced greatly and is much faster than the surface pixel SOM.

#### CS37 Propagation in Aeronautics

Localization & Connected Objects / Convened Session / Propagation
Oral Sessions: Room 352B
Chairs: Uwe-Carsten G. Fiebig (German Aerospace Center (DLR), Germany), Fernando Pérez-Fontán (University of Vigo, Spain)
16:50 L- And C-Band Airframe Shadowing Measurements and Statistics for a Medium-Sized Aircraft
David W Matolak (University of South Carolina, USA); Ruoyu Sun (National Institute of Standards and Technology, USA); Hosseinali Jamal and William Rayess (University of South Carolina, USA)
Airspaces worldwide are becoming more heavily used. This includes the use of unmanned aircraft systems, which is rapidly growing. In order to ensure reliable communication for aircraft, the air-ground channel must be accurately characterized. A significant channel impairment that has not been thoroughly studied is airframe shadowing—obstruction of the line-of-sight signal by the aircraft itself. In this paper, we report on measured results for this shadowing phenomenon in two frequency bands, for a medium-sized aircraft. We present results for two example shadowing events in terms of shadowing depth and duration, and provide distributions of shadowing depth and duration. We show that for both bands, airframe shadowing can be more than 30 dB, and can last for tens of seconds.
17:10 Modeling the Air-Ground Multipath Channel
Nicolas Schneckenburger, Thomas Jost and Uwe-Carsten G. Fiebig (German Aerospace Center (DLR), Germany); Giovanni Del Galdo (Fraunhofer Institute for Integrated Circuits IIS & Technische Universität Ilmenau, Germany); Hosseinali Jamal and David W Matolak (University of South Carolina, USA); Ruoyu Sun (National Institute of Standards and Technology, USA)
The paper proposes a geometrical-statistical modeling approach for the air-ground channel for \ac{CNS} systems in the L-band frequency range. We sketch the architecture of the model with its six elements and show how their parameters can be derived from measurement data. Preliminary results obtained from a relatively small set of measurement data reveal that the proposed modeling approach is well suited to capture the time variant behavior of the channel. However, a considerably more extensive evaluation of the measurement data will be necessary to finalize the parameter settings of the proposed channel model.
17:30 Addressing Scattering From Tree Canopies by PO and MST for Aeronautical and Inland Waterways Scenarios
Milan Kvicera (Czech Technical University in Prague, Czech Republic); Fernando Pérez-Fontán (University of Vigo, Spain); Jonathan Israel (ONERA - The French Aerospace Lab, France); Pavel Pechac (Czech Technical University in Prague, Czech Republic)
A new model addressing scattering from tree canopies is presented in this paper. The model is based on a combination of physical optics and the multiple scattering theory (MST) and provides significant improvements when compared to the case when only MST is utilized, especially the correct near field calculations. The model is validated against MST at 2 GHz and 10 GHz for the case of an artificial scenario and also against a set of experimental data obtained at 2 GHz for a single isolated tree.
17:50 Low Altitude UAV Propagation Channel Modelling
Xuesong Cai (Tongji Unversity, P.R. China); Ana Gonzalez-Plaza and David Alonso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain); Lei Zhang (Universidad Politecnica de Madrid, Spain); Cesar Briso (Universidad Politecnica de Madrid & ETSIS Telecomunicacion, Spain); Antonio Perez Yuste (Technical University of Madrid, Spain); Xuefeng Yin (Tongji University, P.R. China)
The Unmanned Aerial Vehicle (UAV) is going to play an important role in fifth generation communication systems for establishing seamless coverage in various scenarios due to its low- cost and flexibility. Understanding the UAV wireless channels is the basis for its application. In this paper, a recently conducted measurement campaign for the UAV wireless propagation channel in a suburban scenario in Madrid is introduced. Based on the Universal Software-defined Radio Peripheral (USRP) equipment, narrowband measurements at frequency of 5.76 GHz and broad- band measurements at frequency of 1.817 GHz are performed. The path loss, K-factor, power delay profiles (PDPs), multipath components (MPCs) and root-mean-square (RMS) delay spreads (DSs) are presented.
18:10 Using Airborne Measurements to Model the Satellite-to-Aircraft Channel Model at L-Band
Thomas Jost (German Aerospace Center (DLR), Germany); Tanja Pelzmann (École Polytechnique de Montréal, Canada); Martin Schwinzerl (Joanneum Research, Austria); Michael Walter (German Aerospace Center (DLR), Germany); Michael Schönhuber (Joanneum Research, Austria); Nicolas Floury (ESA, The Netherlands)
Radio wave propagation from a satellite based emitter to an airborne located receiver is of interest for applications like passenger internet access during a flight, air traffic management or positioning by global navigation satellite systems (GNSSs). Especially for the last two applications that are related to safety-of-life functionality, accurate channel models for software based system testing are essential. Current state-of-the art channel models for the satellite-to-aircraft case lack of accuracy in terms of modeling all propagation impairments. In this contribution, we describe an airborne experiment using Global Positioning System (GPS) satellite emitted signals to characterize the wave propagation channel from a satellite to an airborne platform. First results on ground reflected multipath are provided.

#### CS43 Signal Processing Techniques to Improve Antenna Characterization Procedures (AMTA/EurAAP)

Methods & Tools / Convened Session / Measurements
Oral Sessions: Room 353
Chairs: Stuart F Gregson (Queen Mary, University of London, United Kingdom (Great Britain)), Laurent Le Coq (University of Rennes 1 & IETR, France)
16:50 GPU-based Computational Acceleration of Phaseless Algorithms for Antenna Characterization
Juan Carlos Fernandez Gonzalez (Universidad de Oviedo, Spain); Miguel Lopez Portugues (Universidad de Oviedo - Area de Teoria de la Señal, Spain); Yuri Álvarez, Jesús Alberto López-Fernández and Fernando Las-Heras (Universidad de Oviedo, Spain)
In the field of antenna diagnosis and characterization, the Sources Reconstruction Method (SRM) has been proved to be a powerful tool enabling the use of arbitrary-geometry measurement and reconstruction surfaces. The SRM has been extended for phaseless antenna characterization using two or more acquisition surfaces, as a simpler (but slower) alternative to holographic techniques. One of the main drawbacks of phase retrieval using multiple surfaces is the need of solving a set of nonlinear equations relating the measured amplitude with a set of equivalent currents using iterative, time-consuming methods. This contribution aims to improve the applicability of this methodology by reducing the time cost of the iterative procedure by means of Graphics Processing Units (GPU). Speed-up rates ranging from 50 to 90 times compared with sequential CPU (Central Processing Unit)-only implementation have been achieved.
17:10 A Novel Approach for Circular Array Testing
Daniele Pinchera and Marco Donald Migliore (University of Cassino, Italy)
In this contribution the use of circular Plane Wave Generator (PWG) for testing large circular arrays is discussed. In particular, it is shown that the synthesis method proposed in the present paper allows the use of a lower number of radiating elements compared with previous PWG approaches.
17:30 Using Partial Information to Predict the Radiation Pattern of an Antenna in Complex Scenarios
Marco Righero (Istituto Superiore Mario Boella, Italy); Giorgio Giordanengo (Istituto Superiore Mario Boella & Politecnico di Torino, Italy); Matteo Alessandro Francavilla (Istituto Superiore Mario Boella, Italy); Francesca Vipiana and Giuseppe Vecchi (Politecnico di Torino, Italy)
A method to characterize an antenna radiation pattern in complex scenarios starting from partial information is described and some preliminary results are shown. In a controlled environment with synthetic data, the method is able to reconstruct the target field with a downsampling of 15 times with respect to Nyquist criterion with negligible errors
17:50 Examination of the Effectiveness of Far-field Mathematical Absorber Reflection Suppression in a CATR Through Computational Electromagnetic Simulation
Stuart F Gregson (Queen Mary, University of London, United Kingdom (Great Britain)); Clive Parini (QMUL, United Kingdom (Great Britain)); Allen Newell and Greg Hindman (Nearfield Systems Inc., USA)
For a little over a decade, a measurement and post-processing technique named Mathematical Absorber Reflection Suppression (MARS) has been used successfully to identify and then suppress range multi-path effects in spherical, cylindrical & planar near-field antenna measurement systems and far-field and compact antenna test ranges (CATR). Much of this early work concentrated on verification by empirical testing however some corroboration was obtained with the use of computational electromagnetic simulations. The recent development of a highly accurate computational electromagnetic simulation tool that permits the simulation of "measured" far-field pattern data as obtained from using CATR has for the first time permitted the careful verification of the far-field MARS technique for a given AUT and CATR combination. For the first time, this paper presents simulated "measured" far-field pattern data in the presence of a large scatterer and then verifies the successful extraction of the scattering artefacts using standard FF-MARS processing.
18:10 Spherical Near-Field Far-Field Transformation with Infinite Ground Plane At Arbitrary Height z
Rasmus Cornelius and Dirk Heberling (RWTH Aachen University, Germany); Dieter Pototzki (Antenna Technology Center Europe & ATC GmbH, Germany)
In measurement scenarios with ground planes the boundary condition has to be included appropriately in the near-field to far-field transformation. For spherical near-field antenna measurements, techniques exist to include a ground plane in the xy-plane z = 0 m. In this paper we will describe a transformation procedure including a translation of the transformation origin, so that the ground plane can be at any height z to overcome that limitation of existing techniques. The procedure is demonstrated by a simulation and measurement example.

#### CS46 The Alphasat Aldo Paraboni Scientific Experiment: Results and Developments after 3 Years of Operations

Space / Convened Session / Propagation
Oral Sessions: Room 362/363
Chairs: Lorenzo Luini (Politecnico di Milano, Italy), Antonio Martellucci (European Space Agency, The Netherlands)
16:50 The ASI and ESA Activities for the Alphasat Aldo Paraboni COMEX and SCIEX Activities at Ka and Q/V Bands
Antonio Martellucci and Juan J. Rivera Castro (European Space Agency, The Netherlands); Philippe Sivac (ESA ESTEC, Germany); Giuseppe Codispoti (Italian Space Agency, Italy); Edoardo Benzi (ESA ESTEC, The Netherlands)
This paper presents an overview of the activities performed by the Agency in the framework of the Alphasat Aldo Paraboni scientific experiment at Ka and Q band. In particular it addresses the technological developments for the equipment of the propagation campaign, the execution of mission related activities, the execution of propagation campaigns, the international cooperation with the group of propagation experimenters and the planning for future activities. The paper is intended to provide the general European background of experimental results published on scientific publications and conferences.
17:10 Large Scale Assessment of Ka/Q Band Atmospheric Channel Across Europe with ALPHASAT TDP5:The Augmented Network
Spiros Ventouras (STFC Rutherford Appleton Laboratory, United Kingdom (Great Britain)); Richard Reeves (Science & Technology Facilities Council & RAL Space, United Kingdom (Great Britain)); Emal Rumi (STFC Rutherford Appleton Laboratory, United Kingdom (Great Britain)); Fernando Pérez-Fontán, Fernando Machado and Vicente Pastoriza (University of Vigo, Spain); Armando Rocha (University of Aveiro & Instituto de Telecomunicações, Portugal); Susana Mota (University of Aveiro & Institute of Telecommunications, Portugal); Flávio M. da Silva Jorge (Instituto de Telecomunicações & Universidade de Aveiro, Portugal); Athanasios D. Panagopoulos, Apostolos Z. Papafragkakis and Charilaos Kourogiorgas (National Technical University of Athens, Greece); Ondrej Fiser (Institute of Atmospheric Physics & Fac. of Electrical Engineering and Informatics/Uni of Pardubice, Czech Republic); Viktor Pek (Institute of Atmospheric Physics CAS, Czech Republic); Petr Pesice (Institute of Atmospheric Physics Prague, Czech Republic); Martin Grabner (Czech Metrology Institute, Czech Republic); Andrej Vilhar and Arsim Kelmendi (Jozef Stefan Institute, Slovenia); Andrej Hrovat (Jožef Stefan Institute, Slovenia); Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium); Alberto Graziani (Université Catholique de Louvain, Belgium); Laurent Quibus (UCL, Belgium); George Goussetis (Heriot-Watt University, United Kingdom (Great Britain))
The upcoming migration of satellite services to higher bands, namely the Ka- and Q-bands offers many advantages in terms of bandwidth, data rates and system capacity. However, it poses challenges as propagation effects introduced by the various atmospheric phenomena are particularly pronounced in these bands and can become a serious constraint in terms of system reliability and performance. This paper outlines the goals, organization and some first results of an ongoing large propagation campaign consortium formed across Europe under the supervision of the European Space Agency; the campaign, shall ultimately assist in the validation and development of channel models targeting these-bands. Finally, the consideration of diverse climatic conditions and elevation angles along with the evaluation of the frequency and spatio-temporal effects, shall support the development of Fading and Mitigation Techniques and their assessment using real data.
17:30 The Joanneum Research SatCom Ka and Q Band Campaigns in Europe and Malaysia
Félix Cuervo (Joanneum Research, Austria); Hong Yin Lam (Universiti Tun Hussein Onn Malaysia, Malaysia); Jafri Din (Wireless Communication Centre, Universiti Teknologi Malaysia); Juan J. Rivera Castro (European Space Agency, The Netherlands); Michael Schmidt (Researcher, Austria); Michael Schönhuber (Joanneum Research, Austria)
In satellite communications, the demand for capacity increase is met by the use of higher frequency bands, which however are severely impaired by atmospheric phenomena (rain, cloud and gaseous attenuation, scintillation). In order to study propagation effects for future satellite communication frequencies both in temperate and tropical climates, JOANNEUM RESEARCH carries out two long-term propagation measurement campaigns, one in Europe with the Alphasat Aldo Paraboni payload at Ka-band (19.7 GHz) and Q-band (39.4 GHz), and another one in two sites in the tropical region of peninsular Malaysia, where the climatic differences affect the propagation channel characteristics. This paper reports on both campaigns and presents the statistical analysis of experimental results and their comparison with the existing ITU-R propagation models.
17:50 Results of a Ka Band Campaign for the Characterisation of Propagation Conditions for SatCom Systems at High Latitudes
Terje Tjelta (UiO, Norway); Martin Rytir and Lars Erling Bråten (Norwegian Defence Research Establishment (FFI), Norway); Per Arne Grotthing (Telenor Satellite, Norway); Michael Cheffena (Gjøvik University College, Norway); Jan Erik Håkegård (SINTEF, Norway)
Satellite services in the High North are utilized extensively for both communication purposes and for earth and climate observations. This paper presents results of two year measurements at 20 GHz and co-sited meteorological data. The results suggest that with 7-8 dB margin, services can be provided with 99 % availability for systems with elevation angles as low as 3.2 deg. Measured attenuation distributions support International Telecommunication Union prediction methods within 3 to 4 dB for 99.99 % of the time. However, scintillation and multipath are not well predicted at the lowest elevation angle.
18:10 Measurement and Modelling of Tropospheric Scintillation in Ka/Q Band
Danielle Vanhoenacker-Janvier (Université catholique de Louvain, Belgium); Laurent Quibus (UCL, Belgium); Martin Rytir (Norwegian Defence Research Establishment (FFI), Norway); Terje Tjelta (UiO, Norway)
The purpose of this paper is to present the use of Numerical Weather Forecast software to generate 4D-meteorological parameters for the characterization and simulation of tropospheric scintillation. The simulator has been tested against scintillation measurements at 30 degree elevation and is used for a further analysis of the turbulence characteristics on a low elevation earth-space link

#### IWS_03: New Over-the-Air Measurement Methods and Design Considerations for Millimeter Wave Antenna Arrays

WG Meetings & WorkShops: Room 315
Chairs: Riccardo Giacometti (Keysight Technologies, France), Pekka Kyösti (Keysight Technologies & University of Oulu, Finland), Moray Rumney (KeysightTechnologies, United Kingdom (Great Britain))

## Wednesday, March 22

### Wednesday, March 22, 08:40 - 12:30

#### CS17 From Pioneering Antenna Contributions to Industrial Applications

Space / Convened Session / Antennas
Room: Oral Sessions: Auditorium Havane
Chairs: Eric Amyotte (MDA, Canada), Giovanni Toso (European Space Agency, The Netherlands)
08:40 Antennas at MDA: Innovation Through Cross-Pollination
This paper presents how several technological advancements in communication satellite antennas have been transferred to other applications and synergistically combined to enable significant reductions in the cost per billable bit of throughput.
09:00 Active Antenna Developments for Telecom Applications at Thales Alenia Space
Eric Vourch (Thales Alenia Space France, France); Christian Féat, Philippe Lepeltier and Fabien Delepaux (Thales Alenia Space, France); Michel Soudet (THALES ALENIA SPACE, France); Jean-Christophe Lafond (Thales Alenia Space, France)
This paper deals with the Active Antenna recent developments in Thales Alenia Space. Current heritage for telecommunication applications is described, focusing on L and S band constellations, reconfigurability in Ku/Ka bands and anti-jamming from X to Ka bands. In addition, key drivers in the active antenna design will be discussed; they will include architecture considerations, efficient software toolings and test techniques to provide a product the closest to the system need. Finally, the recent development of key building blocks are presented and compared to payload market trends for future customer requirements from L to Ka bands.
09:20 Advanced Optimization Techniques for Design, Prototyping and Industrialization of Satellite Antennas: a Space Engineering Perspective
Piero Gabellini (Space Engineering S.p.a., Italy); Gianfranco Ruggerini, Luciano D' Agristina and Domenico Di Lanzo (Space Engineering S.p.A., Italy)
The paper deals with the extensive use of optimization techniques at Space Engineering during the several phases of development of antenna sub-systems for satellite applications
09:40 Satellite Antenna Capabilities Pioneered at Lockheed Martin Space Systems Company
Erik Lier (Lockheed Martin Corporation, USA); Julie Huffman (Lockheed Martin, USA); William N Kefauver (Lockheed Martin & University of Colorado, Boulder, USA); Frank Butscher (Lockheed Martin, USA)
Lockheed Martin Space Systems Company has pioneered advanced antenna solutions over several decades and built a wider range of payload solutions than any other company in the industry. This paper presents a few antenna technologies which has been successfully developed and flown over the years.
10:00 From Modest Multi Beam Towards VHTS: Feed System Evolution at AIRBUS DS GmbH
To illuminate a certain footprint on Earth, a corresponding aperture distribution of the antenna in space needs to be generated. There are various possibilities to generate this distribution. A general classification is for example the distinction between direct radiation and radiation via reflecting apertures. The way how the illumination is realised is directly linked to the complexity of the required feed system. Looking back, one can observe a change from small simple feed systems towards large complicated multifeed arrays, back to simple feeds again. Nowadays we again see the request for large feed systems and complex multifeed arrays. In this paper, we present a short history on antenna systems and the corresponding feed systems over the recent decades. An insight on current feed systems and future products is given.
10:20 Coffee Break
10:50 Antennas for Observation, Exploration and Navigation in ThalesAleniaSpace-Italia: Past and Present Challenges
Roberto Mizzoni and Pasquale Capece (Thales Alenia Space Italia, Italy); Salvatore Contu (Thales Alenia Space, Italy); Alberto Meschini (ThalesAleniaSpace-Italia, Italy); Giovanni Rosati (Thales Alenia Space - Italia, Italy)
The paper provides an overview of the most significant space antenna products and technologies for Observation, Exploration and Navigation (OEN) developed by ThalesAleniaSpace-Italia (TAS-I) over more than 30 years. These antennas provided a determinant contribution to the scientific community in understanding earth environment and solar planets. An outline of today key developments is also presented.
11:10 Heritage of Mitsubishi's Phased Array Antennas Development for Mobile Satellite Communications
Hiroyuki Sato and Hiroaki Miyashita (Mitsubishi Electric Corporation, Japan)
This paper introduces the heritage of Mitsubishi's phased array antennas(PAA's) development focusing on mobile satellite communication terminals from commercialization of product standpoint.
11:30 Product Concepts for Land Mobile Satellite Communication Terminals in Ku-/Ka-Band
Nevena Saponjic (Viasat Antenna Systems SA, Switzerland); Frank Klefenz (ViaSat Antenna Systems SA, Switzerland); Frédéric Bongard (Viasat Antenna Systems SA, Switzerland); Daniel Llorens (ViaSat Antenna Systems SA, Switzerland); Alexandre Boulle, Xavier Aubry and Alexander Butler (Viasat Antenna Systems SA, Switzerland); Ferdinando Tiezzi and Stefano Vaccaro (JAST SA, Switzerland)
The details of two product concepts and the hardware realization aspects for low profile Ku and Ka band land mobile terminals for high data rate satellite communications are described. Beside the competitive low cost approach, the non-obstructive design and lower weight are key issues for many applications to achieve a broad customer acceptance. The introduction of a proprietary planar antenna technology opens the possibility to meet these requirements.
11:50 Asymptotic Formulas for the Radiation of a Dipole on a Strongly Elongated Convex Body:A Review
Frederic Molinet (SARL MOTHESIM, France)
In this paper, the author gives a review on some asymptotic formulas which have been developed by different authors during the last ten years, for the field radiated by a source located on a strongly elongated convex body of revolution. Both perfectly conducting and impedance boundary conditions are considered. Explicit asymptotic solutions for the field on the surface in the paraxial direction are presented. Some numerical results on a spheroid are shown.
12:10 A Collective UTD Ray Analysis for the Radiation from Conformal Linear Phased Array Antennas on Large Cylindrical Surfaces
Prabhakar H. Pathak (The Ohio State University, USA)
A collective Uniform Geometrical Theory of Diffraction (UTD) solution is developed for describing, in a simple fashion, the radiation from a periodic, finite but long, linear array of elemental antennas mounted conformally on a larger canonical circular cylinder geometry which is assumed to be a perfect electric conductor (PEC). This work is relevant to the prediction of the performance of large and conformal electronically scanned phased arrays in modern applications. The collective UTD radiation field of the entire array in the presence of the cylinder, when observed at any point which is not too close to the array, is vividly described here in terms of just three propagating rays; one such ray arrives to an external observation point from an appropriate point within the array interior, while the remaining arrive from each of the two ends of the linear array, respectively.

#### CS44 Small Antennas: From Theory to Practice

Wireless Networks / Convened Session / Antennas
Oral Sessions: Room 341
Chairs: Eva Antonino Daviu (Universidad Politécnica de Valencia, Spain), Miloslav Capek (Czech Technical University in Prague, Czech Republic)
08:40 Recoverable Energy and Small Antennas
Guy A. E. Vandenbosch (Katholieke Universiteit Leuven, Belgium); Jiachen Wang (KU Leuven, Belgium)
The maximum "recoverable" energy of a small radiator is determined. This energy is defined as the maximum energy that can be recovered from the electromagnetic field distribution in entire space generated by the radiator up to the time point considered. It is shown that the concept of recoverable energy for small radiators leads to a quasi-constant future current. The question can be raised whether this "recoverable" energy can be identified with the stored energy for a small radiator.
09:00 Minimum Q-factors for Antennas
Mats Gustafsson (Lund University, Sweden); Miloslav Capek (Czech Technical University in Prague, Czech Republic)
Optimization of antenna currents is used to determine lower bounds on the Q-factors for antennas. Minimum Q-factors for antennas with specified radiation patterns are reformulated in convex form and are hence easily solvable. Here, it is shown that the unconstrained case with minimum Q can be relaxed to a dual problem that is solved as a generalized eigenvalue problem. This dual problem determines the minimum Q-factors for problems without degenerate eigenvalues. Moreover, cases with degenerate eigenvalues are solved by perturbations of the problems.
09:20 Overcoming the Chu Lower Bound on Antenna Q with Highly Dispersive Lossy Material
Arthur D Yaghjian (Electromagnetics Research Consultant, USA)
It is demonstrated by means of RLC circuit models of electrically small antennas that their isolated-resonance quality factors obtained from the "Q-energy" predicts their bandwidths with greater accuracy than the "equivalent-circuit" or the "electrodynamic" energies. Moreover, it is verified that the Q-energy cannot be considered stored energy in highly dispersive lossy material. Nonetheless, using tuning elements containing highly dispersive lossy material, the bandwidth of fifty-percent efficient electrically small dipole antennas can be designed with twice the bandwidth predicted by the Chu lower bound for the quality factor of fifty-percent efficient antennas.
09:40 Antenna Q Bounds for Given Directivity: a Case Study of a Directive Parasitic Element Antenna
Lars Jonsson (KTH Royal Institute of Technology, Sweden); Fabien Ferrero (University Nice Sophia Antipolis, CNRS, LEAT & CREMANT, France); Leonardo Lizzi (Université Côte d'Azur, CNRS, LEAT, France)
In certain communication applications it is advantageous to constrain the shape of the far-field, as to make it act as a spatial filter. This can mitigate interference from other antennas. Such constraints on the far-field behavior, in particular for small antennas tend to increase antenna Q rapidly. To begin to investigate the relation between antenna Q and such far-field bounds, we here consider a case-study with constraint on the partial realized directivity for a two and three parasitic element antenna. The aim is to compare these predictions with a realized parasitic element antenna of the same shape. Note that this paper is a work in progress, and the final comparison between the realized antenna and the fundamental limitations will be discussed at the presentation.
10:00 Small 4 Elements Bi-Directional Antenna for Indoor MIMO Base Station
Rohani Bakar, Kanata Takahashi and Hiroyuki Arai (Yokohama National University, Japan); Yasuko Kimura and Taisuke Ihara (NTT DoCoMo, Inc., Japan)
A composite antenna of a notch antenna and a loop antenna has been developed for indoor MIMO base station. The composite antenna has dual polarized radiation patterns pointing to two different directions. The horizontally polarized wave is given by the notch element in x-axis direction while the vertically polarized wave is given by the loop element in y-axis direction. The combination of the two composite antennas produces dual polarized radiation patterns in bi-direction and has a good isolation between the elements. This MIMO antenna is designed for 4G applications with the resonance frequency at 3.5 GHz.
10:20 Coffee Break
10:50 Body-Worn 67:1 Bandwidth Antenna Using 3 Overlapping Dipole Elements
Cedric Lee (The Ohio State University, USA); Dimitris Papantonis (Ohio State University, USA); Asimina Kiourti (The Ohio State University, USA); John L. Volakis (Ohio State University, USA)
We present a novel tightly coupled dipole array (TCDA) that achieves 67:1 bandwidth over the 30 MHz to 2 GHz frequency range. The design is extremely simple, and consists of 3 overlapping dipoles that are fed at 3 different locations to ensure uniform current flow. The overlapping dipoles are "printed" on a 0.3 mm-thick polymer substrate (εr=3), and "sandwiched" between two layers of flexible polymer (εr=3), each 2 cm thick. The TCDA occupies 1.4 m x 0.09 m, and is intended for on-body operation (e.g., placed along the arms). For example, the proposed antenna could be integrated into military uniforms to enhance quality of service in the SINCGARS, Air and Marine, UHF, UHF-Public Safety, and L bands.
11:10 Electrically Small Metamaterial-Inspired Antennas with Active Near Field Resonant Parasitic Elements: From Theory to Practice
Ming-Chun Tang (College of Communication Engineering, Chongqing University, Chongqing, P.R. China); Richard W. Ziolkowski (University of Arizona, USA)
By augmenting several classes of metamaterial-inspired near-field resonant parasitic (NFRP) electrically small antennas (ESAs) with active (non-Foster) circuits, we have achieved performance characteristics surpassing their fundamental passive bounds. The designs not only have high radiation efficiencies, but they also exhibit large frequency bandwidths, large beam widths, large front-to-back ratios, and high directivities. Furthermore, the various initially theoretical and simulated designs have led to practical realizations. These active NFRP ESAs will be reviewed and recently reported designs will be introduced and discussed.
11:30 Propagation Considerations for Implantable Antennas
Anja K. Skrivervik (EPFL, Switzerland); Marko Bosiljevac and Zvonimir Sipus (University of Zagreb, Croatia)
The use of Body Area Networks has been increasing in the past decade due to the emergence of novel wearable and implantable services in the frame of e.g. healthcare, sports, security or fashion. As a result, the number of wearable and implantable antenna designs has exponentially increased in the same time frame. After this first boom in research related to W-BAN antennas, it is now time to learn from the achieved results, and try to understand the mechanisms limiting the performances of such radiators, in order to finally be able to develop useful practical design rules. In this contribution, we introduce a theoretical analysis of some canonical implanted W-BAN electromagnetic source scenarios, using a specifically developed numerical tool based on spherical wave expansions. The obtained results are used to give some design criteria for implantable antennas.
11:50 Small Printed Log-Periodic Array, Matched with an Active non-Foster Network
Fernando Albarracín-Vargas (Universidad Carlos III de Madrid, Spain); Francisco Javier Herraiz-Martínez (Carlos III University in Madrid, Spain); Daniel Segovia-Vargas (Universidad Carlos III de Madrid, Spain)
The design of a small printed-log-periodic antenna, loaded with an active matching network, for multiband applications is presented. A well-known, low-cost and low-profile antenna is re-engineered for including an additional impedance bandwidth in the lower UHF-band. The design method includes the use of the recently introduced sensitivity parameter Sens in order to find a suitable location for a transistor-based non-Foster network, realized with a Negative Impedance Converter (NIC).
12:10 Fano Matching Bandwidth Bounds for Small Loop Antennas Based on Spherical Wave Scattering
Do-Hoon Kwon (University of Massachusetts Amherst, USA)
Fundamental impedance matching bounds for electrically small loop antennas are derived based on spherical wave scattering in the low-frequency limit. A small lossless loop antenna is represented as a two-port network between the excitation port and the fundamental TE spherical wave port. The low-frequency asymptotic expression for the wave reflection coefficient is found and the classical Fano approach is applied to derive integral equalities for the magnitude of the reflection coefficient. A basic loop, one with a series-C element, and one with a parallel-C element are analyzed. The bandwidth upper bounds as functions of the antenna dimension, the port impedance, and the circuit parameters are presented.

### Wednesday, March 22, 08:40 - 10:20

#### C_P03 Urban Propagation

Cellular Communications / Regular Session / Propagation
Oral Sessions: Room 342A
Chairs: Jan M. Kelner (Military University of Technology, Poland), Taghrid Mazloum (Telecom ParisTech, France)
08:40 Investigation of Distributed and Collocated Base Stations in a Large Urban Massive MIMO Scenario
Mehmet Mert Taygur (Technical University of Munich, Germany); Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany)
An investigation of two Massive Multiple-Input Multiple-Output (MIMO) scenarios, with distributed and collocated transmitter antenna cases for a large dense urban environment, is performed based on ray tracing simulations. The scenarios consist of maximum 4096 transmitter antennas and 500 single antenna users which are at the ground level. The environment is one quarter square kilometre large and consists of 92 buildings with various heights. Channel matrices are obtained using ray tracing simulations. Maximum Ratio Transmission (MRT) and Minimum Mean Square Error (MMSE) linear beamformers are implemented during the post processing. The downlink performances are investigated. The results indicate that the variation of performance among the users can be different even though the average performance figures are not significantly different for the given deployment schemes.
09:00 Modeling the Distribution of the Arrival Angle Based on Transmitter Antenna Pattern
Cezary Ziółkowski, Jan M. Kelner, Leszek Nowosielski and Marian Wnuk (Military University of Technology, Poland)
An angular distribution of received signals has a significant impact on their spectral and correlational properties. Most of angular dispersion models do not consider antenna patterns. The developed procedure for determining the propagation path parameters enables a wide range of assessment of the impact of the propagation environment on the received signal properties. In contrast to the other models, this procedure is based on a geometrical structure, which parameters are defined on the basis of power delay profile or spectrum This modeling method allows also the power radiation pattern (PRP) of the transmitting antenna. The aim of the paper is to present the influence of the transmitter antenna PRP on the scattering propagation paths that arrive at the receiver. This analysis is realized on the basis of simulations studies using the developed procedure. Presented in this paper procedure maps the effects of propagation phenomena that predominate in an azimuth plane.
09:20 Investigating the Overestimation of Base Station Exposure in Urban Environments Due to Assumption of Free Space Propagation
Thomas Kopacz, Sascha Schießl and Dirk Heberling (RWTH Aachen University, Germany)
Safety assessment of exposure caused by cellular base stations based on calculation methods is often performed using free space propagation in order to include the worst case. For prospective technologies (e.g. small cells in the vicinity of people), this approach might lead to a high exploitation of exposure limits. This paper investigates the overestimation of downlink exposure being predicted with a free space propagation model in comparison to a deterministic 2D knife edge diffraction model in an urban environment for a rooftop mounted base station. The results show that overestimation is quite low in the vicinity of the base station, particularly in LOS regions. In a distance between 100 and 200 m the overestimation is constantly rising, whereas for distances larger than 200 m it stays nearly constant.
09:40 Assessment of RF Human Exposure to LTE Small- And Macro-Cells: UL Case
Taghrid Mazloum (Telecom ParisTech, France); Bader Fetouri (Mobile Networks CTO - Nokia, France); Nabil Elia (ANFR, TelecomParisTech, France); Emmanuelle Conil (ANFR, France); Christophe Grangeat (Mobile Networks CTO - Nokia, France); Joe Wiart (Telecom ParisTech, France)
Small cells, novel low-powered base stations with local range, are nowadays investigated in order to improve the radio coverage and capacity in macro cell layer. The radio frequency exposure induced in such cells is unknown. Hence, we assess in this paper, through experimental measurements, the impact of an LTE small cell cluster on the radio frequency exposure induced by a mobile handset. With respect to macro cells, we show that the deployment of small cells provides better radio coverage in terms of throughput while minimizing the radio frequency exposure induced by the mobile handset.
10:00 Analysis of the Level-Crossing Rate and Average Duration of Fades of WSSUS Channels
Matthias Pätzold (University of Agder, Norway); Nazih Hajri (Ecole Supérieure de Communications de Tunis, Sup'Com, Tunisia); Neji Youssef (Ecole superieure des communications de Tunis, Tunisia)
Studies of the level-crossing rate (LCR) and the average duration of fades (ADF) are so far only devoted to stochastic processes being a function of one independent variable, which is usually time or in some few cases frequency. In this paper, we study the LCR (ADF) of wide-sense stationary uncorrelated scattering (WSSUS) processes in the time-frequency domain. A closed-form solution will be derived for the so-called time-frequency LCR (ADF) of the absolute value of the time-variant transfer function (TVTF) of WSSUS processes. It is shown that the LCR (ADF) is circularly symmetric in the normalized time-frequency domain. The derived time-frequency LCR contains the time LCR and frequency LCR well known in the literature as special cases. The importance of the introduced time-frequency LCR is demonstrated by introducing a new method for the estimation of the Doppler spread and the delay spread from measured TVTFs of WSSUS channels.

#### B_P01 Biomedical Imaging

Biomedical / Regular Session / Propagation
Oral Sessions: Room 342B
Chairs: Panagiotis Kosmas (King's College London, United Kingdom (Great Britain)), Andrea Massa (University of Trento, Italy)
08:40 Multi-Resolution Compressive Sensing Inversion of Scattering Data
Lorenzo Poli (University of Trento, Italy); Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy); Andrea Massa (University of Trento, Italy)
This paper proposes a novel technique for retrieving the dielectric features of weak scatterers in microwave imaging by means of a Compressive Sensing (CS)- based method enhanced by a multi-zoom strategy. A Relevance Vector Machine (RVM) is used to invert the data of the problem recast in a Bayesian framework, exploiting the combination of the a-priori information on the sparseness of the unknowns and the acquired knowledge during the iterative multi-scaling methodology. Representative results are presented to illustrate advantages and limitations of the proposed method.
09:00 Inverse Source and Compressive Sensing for Qualitative Reconstruction
Martina Teresa Bevacqua and Tommaso Isernia (University Mediterranea of Reggio Calabria)
A new linear approach for support reconstruction of both penetrable and impenetrable objects from the measurements of the scattered fields is introduced and described. The approach takes advantage from the fact that for both high conductivity and dielectric scatterers, induced and 'equivalent' currents can be considered localized on the boundary. Starting from these considerations, an ad hoc compressive sensing inspired inversion approach is formulated to localize and retrieve the shape of the unknown objects without a priori assumptions on them.
09:20 Exploiting Wavelet Decomposition to Enhance Sparse Recovery in Microwave Imaging
Michele Ambrosanio (Università di Napoli Parthenope, Italy); Panagiotis Kosmas (King's College London, United Kingdom (Great Britain)); Vito Pascazio (Università di Napoli Parthenope, Italy)
Over the last years, various new non-invasive methodologies have been proposed for medical imaging. Among them, microwave imaging (MWI) seems to be a promising technique for applications such as stroke detection and breast cancer imaging (BCI). This diagnostic modality is based on measurements of the scattered field outside an imaging domain, in which the object of interest is located. This inverse problem requires strategies such as regularization to increase the stability of the reconstructions. This work presents a method to increase stability based on exploiting the wavelet transform (WT) as a regularization strategy combined with a sparsity-based approach. The proposed technique is based on the theory of compressed sensing (CS) to treat the strong ill-posedness of the non-linear electromagnetic inverse scattering (EIS) problem.
09:40 A Compressive Sensing Unmixing Algorithm for Breast Cancer Detection
Jose Martinez Lorenzo and Richard Obermeier (Northeastern University, USA)
In this paper, we describe a novel unmixing algorithm for detecting breast cancer. In this approach, the breast tissue is separated into three components, low water content (LWC), high water content (HWC), and cancerous tissues, and the goal of the optimization procedure is to recover the mixture proportions for each component. By utilizing this approach in a hybrid DBT / NRI system, the unmixing reconstruction process can be posed as a sparse recovery problem, such that compressive sensing (CS) techniques can be employed. A numerical analysis is performed, which demonstrates that cancerous lesions can be detected from their mixture proportion under the appropriate conditions.
10:00 Application of the DBIM-TwIST Algorithm to Experimental Microwave Imaging Data
Zhenzhuang Miao (KING'S COLLEGE LONDON, United Kingdom (Great Britain)); Syed Ahsan and Panagiotis Kosmas (King's College London, United Kingdom (Great Britain)); Jorge Alberto Tobon Vasquez, Francesca Vipiana, Mario Roberto Casu and Marco Vacca (Politecnico di Torino, Italy)
This work presents some preliminary results from applying our previously developed microwave imaging algorithm based on two-step iterative shrinkage/thresholding (TwIST) to data measured from an experimental microwave imaging system. Combining the distorted Born iterative method (DBIM) with the TwIST linear solver, our two-dimensional (2-D) algorithm is applied to reconstruct 2-D slices of the complex permittivity of the interrogated imaging domain. Experimental data are obtained by rotating a two-antenna system along the cylindrical imaging domain, which is filled with Triton X-100. The imaging object is an anatomically realistic breast phantom with a tube filled water representing the tumor-like target. Measurements are covered in the frequency range from 0.5 to 4.0 GHz. The paper presents reconstructed images at 900 MHz, while more results will be presented at the conference.

### Wednesday, March 22, 08:40 - 12:30

#### CS48 THz Wireless Communications: from Components to Systems

High Data-rate Transfer / Convened Session / Antennas
Oral Sessions: Room 343
Chairs: Guillaume Ducournau (IEMN - Lille University, France), Frédéric Gianesello (STMicroelectronics, France)
08:40 Terahertz Communications Using Resonant-Tunneling-Diode Oscillators
Safumi Suzuki (Tokyo Institute of Technology, Japan)
The recent progress in terahertz wireless data transmissions using resonant-tunneling-diode (RTD) oscillators is reported. RTD oscillators with wide modulation bandwidth (~30 GHz) were fabricated, and wireless data transmissions in the 500-GHz range were demonstrated. An error-free transmission data rate up to 22 Gbps and a transmission with bit error rate less than the forward error correction limit, up to 34 Gbps, were achieved. For alignment-free wireless communication in the polarization direction, an RTD oscillator integrated with a radial line slot antenna for circular-polarized radiation was proposed and fabricated. A sharp directivity and low axial ratio of polarization (2.2 dB) was achieved at 710 GHz.
09:00 Signal Quality Impairments by Analog Frontend Non-Idealities in a 300 GHz Wireless Link
Ingmar Kallfass, Seyyid Dilek and Iulia Dan (University of Stuttgart, Germany)
This paper discusses the influence of non-idealities in the analog transmit and receive frontend of an MMIC-based 300 GHz wireless link on the receive signal quality. The degradation of EVM due to limited bandwidth and gain imbalance in the quadrature up- and down-converters is considered and compared to experimentally achieved data. Using adaptive equalization and quadrature error correction in the digital baseband, the measured EVM in a 1 m data transmission is improved by up to 4.5 dB from its raw value and stays below ‑12.75 dB for data rates of up to 36 Gbit/s with QPSK modulation. A frequency dependent theoretical analysis of quadrature gain imbalance allows to derive its impact on receiver EVM as a function of baud rate.
09:20 Scattering Center Determination for Integrated Antenna Measurements at mm-Wave Frequencies
Linus Boehm (Ulm University, Germany); Christian Waldschmidt (University of Ulm, Germany)
In this paper the results of integrated antenna measurements are analyzed to identify the main reflection locations when measuring with wafer probes. Two different approaches are described and the measurement results for two different probe designs are shown. First, the main reflection center on the wafer probe is determined by analyzing the measured far field radiation pattern at 160 GHz. The second approach is based on an extrapolation measurement of the antenna. It is shown that the reflective areas can be identified for both probe designs. The results can be used to assess the measurement uncertainty and to quantify the measurement error.
09:40 Artificial Dielectric Enabled Antennas for High Frequency Radiation From Integrated Circuits
Daniele Cavallo, Waqas Hassan Syed and Andrea Neto (Delft University of Technology, The Netherlands)
At millimeter and sub-millimeter wave frequencies, electronic circuits and antennas are often located on the same semiconductor chip to facilitate their interconnection. However, on-chip antennas are characterized by very poor radiation efficiency and extremely narrow bandwidth. This is because they are situated at small electrical distance from a ground plane that shields the antenna from the lossy bulk. High-permittivity superstrates can be located above the antennas to improve the impedance properties, but they support the propagation of surface waves which reduce the efficiency. Here we propose the use of artificial dielectric (AD) superstrates above the antennas to improve significantly their performance. Because of their anisotropy, AD slabs do not support surface waves, thus enabling high-efficiency designs. To clarify the concept, we investigate the property of a simple dipole antenna on chip in terms of impedance and efficiency. Full-wave simulations predict efficiency up to 87% with the presence of the AD.
10:00 Performance Evaluation of a First Phased Array Operating at 300 GHz with Horn Elements
Sebastian Rey (Technische Universität Braunschweig, Germany); David Ulm and Thomas Kleine-Ostmann (Physikalisch-Technische Bundesanstalt, Germany); Thomas Kürner (Technische Universität Braunschweig, Germany)
The application of frequencies beyond 300 GHz in the so-called THz frequency range requires electronic beam steering, which can be realized by a phased array.In this paper, measurement results of a novel 300 GHz phased array antenna with horn elements and an envisagde gain of 20.7 dBi for THz communications are presented.The results are compared to simulations with respect to antenna patterns, gain, half power beam width, frequency dependenceof these and the matching of the antenna elements. An outlook towards measurements of antenna patterns of the array as a whole concludes the paper.
10:20 Coffee Break
10:50 Photonic Generation and Distribution of Coherent Multiband THz Wireless Signals
Martyn Fice (University College London, United Kingdom (Great Britain)); Haymen Shams (University College London (UCL), United Kingdom (Great Britain)); Zhen Yang, Luis Gonzalez-Guerrero, Michele Natrella, Cyril Renaud and Alwyn Seeds (University College London, United Kingdom (Great Britain))
We discuss photonic generation of high-speed THz wireless signals, with particular reference to how multiband signals could be distributed over fibre networks from a central baseband unit equipped with a pool of optoelectronic components, allowing the remote antenna unit to be very simple, while delivering flexibility in terms of data rate and THz carrier frequency. The proposed scheme is demonstrated experimentally by generating a 5-channel multiband signal with aggregate data rate of 100 Gb/s and investigating the performance of each 20 Gb/s sub-band after transmission over a wireless link in the 220 - 280 GHz band.
11:10 High Efficiency UTC Photodiodes as Photonic Emitters for 300 GHz High Spectral Efficiency Wireless Communications
Philipp Latzel (IEMN, France); Fabio Pavanello (IEMN, CNRS/LILLE 1, France); Sara Bretin and Maximillien Billet (IEMN, France); Emilien Peytavit (IEMN, CNRS, France); Jean-François Lampin (Lille University, France); Mohamed Zaknoune (Institute of Electronics, Microelectronics and Nanotechnology, France); Guillaume Ducournau (IEMN - Lille University, France)
This paper presents the development and use of high-efficiency Unitravelling carrier photodiodes for THz communications. Using these devices, high output power is obtained close to the mW level. THz wireless links demonstration is also presented using these devices, using high-level modulation schemes (QAM-16) and 32 Gbit/s data-rate. This result demonstrates the capability of the UTC-PD devices of combining high power level and a linear behavior, mandatory for high-spectral efficiency data links in the THz range.
11:30 Enabling Low Cost THz Radiating Source Leveraging Si Photonics, IC Packaging Substrate & 3D Printing Technologies
Elsa Lacombe (University of Nice Sophia Antipolis & STMicroelectronics, France); Frédéric Gianesello (STMicroelectronics, France); Cyril Luxey (University Nice Sophia-Antipolis, France); Cedric Durand and Daniel Gloria (STMicroelectronics, France); Aimeric Bisognin (University Nice Sophia-Antipolis & STMicroelectronics, France); Diane Titz (University Nice Sophia Antipolis, France); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal)
Silicon technologies enable today the development of cost effective millimeter-wave applications (60 GHz wireless link for example). In order to achieve higher data rates (> 10 Gb/s), we can now consider the sub-THz frequencies in order to take advantage of wider frequency bands. In this context, the development of low cost and highly integrated Si-based sub-THz wireless chipset is a hot topic; industrial Si Photonic PIN Photo-Diode can be used as sub-THz source. But a key challenge is the design of antennas and packages able to support ultra-broad band sub-THz transmission in a cost effective manner. We propose here the design of a 200-280 GHz antenna integrated in an organic substrate packaging technology. Simulated performances exhibit a gain of >8 dBi over a 33% bandwidth. A 3D printed plastic lens is then added to the system in order to increase the achievable gain up to 20 dBi.
11:50 Interconnect and Packaging Technologies for Terahertz Communication Systems
Goutam Chattopadhyay (JPL, USA); Theodore Reck and Cecile Jung-Kubiak (NASA-JPL, Caltech, USA); Maria Alonso-delPino (Jet Propulsion Laboratory, USA); Choonsup Lee (JPL, USA)
Using newly developed silicon micromachining technology that enables low-loss and highly integrated packaging solutions, we are developing vertically stacked transmitters and receivers at terahertz frequencies that can be used for communication and other terahertz systems. Although there are multiple ways to address the problem of interconnect and packaging solutions at these frequencies, such as system-on-package (SOP), multi-chip modules (MCM), substrate integrated waveguide (SIW), liquid crystal polymer (LCP) based multilayer technologies, and others, we show that deep reactive ion etching (DRIE) based silicon micromachining with vertical integration allows the most effective solutions at terahertz frequencies
12:10 Fly's Eye Spherical Antenna System for Future Tbps Wireless Communications
Nuria LLombart and Diego Emer (Delft University of Technology, The Netherlands); Marta Arias (Delft University of Technology, Germany); Earl McCune (RF Communications Consulting & Eridan Communications, USA)
In this work we present an antenna system capable of providing wireless data rates orders of magnitude above the current mobile solutions with a comparable RF power requirement. The proposed solution is based on a sphere shaped 2D (two-dimensional) lens antenna array that generates multiple-directive beams. A full 360deg coverage is achieved via a combination between Space Division Multiplexing (SDM) and a 4 channel frequency re-use. As a test case scenario, we tackle future capacity demands in sport stadiums during high-profile matches. Each antenna directive beam links a set of users/spectators sitting in the stadium tribune with a central base station. The use of multiple high frequencies line of sight links (120GHz) makes possible wireless data rates of 12Tbps to serve 80.000 users with a reasonable overall radio frequency (RF) power consumption (≈ 50W) and user terminal transmit power (≈15dBm).

#### CS27 Mm-wave GAP Waveguide Technology

Future Applications / Convened Session / Antennas
Oral Sessions: Room 351
Chairs: Ahmed Kishk (Concordia University, Canada), Jian Yang (Chalmers University of Technology, Sweden)
08:40 New Feeding Network Topologies for High-Gain Single-Layer Slot Array Antennas Using Gap Waveguide Concept
Miguel Ferrando-Rocher, Alejandro Valero-Nogueira and José Ignacio Herranz-Herruzo (Universidad Politécnica de Valencia, Spain)
This paper describes a low-loss ridge gap waveguide (RGW) to groove gap waveguide (GGW) transition. Transitions from RGW to GGW and vice versa can be advantageously combined leading to very compact feeding networks. Interestingly, these transitions circumvent the 180 deg phase difference in E-plane power splitters, facilitating in-phase corporate feeding networks based on such dividers. Using these transitions a first prototype of a 4x4 single-layer slot array antenna is presented. This antenna exhibits several appealing features for contemporary applications: single-layer, compact, symmetrical, and both radiation pattern bandwidth and impedance bandwidth greater than 14 % at V-band (57-66 GHz).
09:00 Wideband Glide-symmetric Holey Structures for Gap-waveguide Technology
Mahsa Ebrahimpouri (KTH Royal Institute of Technology, Sweden); Eva Rajo-Iglesias (University Carlos III of Madrid, Spain); Oscar Quevedo-Teruel (KTH Royal Institute of Technology, Sweden)
In this paper, the stop-band of two different holey glide-symmetric EBG lattices is studied. The results show that glide-symmetric EBG structures have potential to achieve wide stop-bands by polygonal lattices. Potential application of the proposed EBG structure in gap-waveguide technology is discussed in the second part of the paper.
09:20 Design of Antenna Feed with Amplified Power Distribution Using Groove-Gap Waveguide Technology
A contactless in-line wideband and low-loss microstrip to groove-gap (GG) waveguide transition based power divider operating at X-band is presented. It can be scaled to mm-wave frequencies and beyond without too many mechanical problems, due to the innovative Gap Waveguide technology. The principle of operation is based on transforming EM fields from a SIW to a groove-gap (GG) waveguide mode via near field electromagnetic coupling. This is advantageous since the proposed solution avoids the use of metal contact between the SIW and one of the waveguide parts. Furthermore, metamaterial-based gap waveguide technology provides a resonance-free packaging solution for the integrated MMIC amplifier. We propose to use this transition in a power divider scheme to provide distributed power amplification in groove-gap (GG) waveguide technology to be applied to antenna systems in this same technology.
09:40 Gap Waveguide Based Planar Antenna for 140 GHz (D-band)
Sofia Rahiminejad and Ashraf Uz Zaman (Chalmers University of Technology, Sweden); Sjoerd Haasl (Royal Institute of Technology, Sweden); Peter Enoksson (Chalmers University of Technology, Sweden)
This paper presents a polymer gap waveguide antenna operating at 140 GHz (D-band). The antenna has three layers and all are suitable for MEMS fabrication. The polymer SU8 will be used for all these layers and after they will be coated with gold. In this paper the top plate is fabricated and is presented together with the design, simulation results, and the fabrication process. The design of the complete antenna shows a simulated reflection coefficient bandwidth of about 15% (S11 < -10 dB), and a simulated directivity of about 34 dBi. Index Terms—Antenna, Microsystem technology, D-band, SU8.
10:00 High Gain Circularly Polarized Slot Antenna Based on Microstrip-ridge Gap Waveguide Technology
Fangfang Fan and Zehong Yan (Xidian University, P.R. China)
This paper presents a novel circular polarized slot antenna design using microstrip-ridge gap waveguide technology, it possesses the easy manufacturing since it realizes the gap waveguide with PCB process. The antenna is composed of two substrates, by using the ring slot with a shorted strip on the upper substrate and the EBG textures located on the lower substrate, the circular polarized characteristic of the antenna is obtained, the simulated results with CST simulation software show the antenna has the impedance bandwidth of 13.8% (72.1GHz-82.8GHz, |S11|<-10dB), and the axial ratio is from 75.2GHz-79.9GHz (AR<3dB) with 6% circular polarization bandwidth. And also the microstrip slot antenna is designed and compared with the antenna in this paper. The compared results give the strong evidence that the microstrip-ridge gap waveguide circular polarized slot antenna has wider bandwidth and higher gain.
10:20 Coffee Break
10:50 W-band Wideband and High-Gain TE220-Mode Cavity-excited Circularly Polarized Antenna Array with Gap Waveguide Feeding Network
Hao Wang (Nanjing University of Science & Technology, P.R. China)
In this communication, a TE220 mode substrate integrated cavity (SIC) excited 2×2 circularly polarized (CP) antenna subarray for wideband and high-gain W-band array application is presented. This antenna subarray is designed by using of two low-cost double-side printed circuit broads (PCBs). By combining the rectangular slot and L-shaped probe, a CP antenna can be achieved. The transmission loss caused by divider can be reduced by using the high order mode substrate integrated cavity to excite the slot antenna subarray. Furthermore, such use reduces processing difficulty and fabrication cost. To reduce the loss further, the microstrip-based ridge gap waveguide (GWG) technology is applied to feed the SIC subarrays. Moreover, a linear polarization (LP) slot antenna is also designed to illustrate the operation mechanism of the proposed CP antenna. To validate our design, an 8×8 antenna array with 4×4 SIC subarrays has been fabricated and measured.
11:10 Characteristics of 3D Printed Gap-Waveguide Components
Zoran Eres (Rudjer Boskovic Institute, Croatia); Mladen Vukomanovic, Marko Bosiljevac and Zvonimir Sipus (University of Zagreb, Croatia)
Novel manufacturing technologies such as additive manufacturing or 3D printing allow many simplifications in the production of electromagnetic components. In this paper we focus on the characteristics of the components based on gap-waveguide technology and manufactured using 3D printing after which chemical copper electro-plating is performed. This is important since gap-waveguides are quite complex structures from manufacturing point of view due to multiple small metallic parts. For this purpose we have designed a groove gap-waveguide demonstrator at 10 GHz and a novel gap-waveguide leaky-wave antenna at 30 GHz which can be easily integrated with both the new gap waveguide and the traditional waveguide technology. Through simulations and measurements we will try to highlight the benefits and problems of this 3D technology in the high-frequency components prototyping.
11:30 Millimeter Wave Contactless Microstrip-Gap Waveguide Transition Suitable for Integration of RF MMIC with Gap Waveguide Array Antenna
Uttam Nandi, Ashraf Uz Zaman, Abbas Vosoogh and Jian Yang (Chalmers University of Technology, Sweden)
A new simple transition from a microstrip to gap waveguides has been proposed in this paper. The transition has been implemented for ridge gap waveguide and a groove gap waveguide. The cavity coupling is used to couple the waves between the microstrip and the gap waveguides. This cavity acts as a backshort in the transition region and the microstrip lies inside the waveguide, which provides a solution to integration of RF MMIC circuits with the feed-network of the gap waveguide array antenna. Roger 3010 (Er=10.2) was used as the microstrip substrate for these transitions. The optimised back-to-back Ridge Gap Waveguide (RGW)-microstrip transition shows relative bandwidth of 21% for S11<20 dB and Groove Gap Waveguide (GGW)-microstrip transition shows relative bandwidth of 20% for S11<17 dB. The insertion losses are better than 0.5 dB in the designed frequency bands for both the RGW and GGW transitions.
11:50 A K-Band Planar Slot Array Antenna on a Single Layer Ridge Gap Waveguide
Zeinab Talepour (K. N. Toosi University of Technology, Iran); Ali Khaleghi (K.N.Toosi University of Technology)
A K-band slot array antenna is developed by using ridge gap waveguide technology in a single layer metal structure. A power divider of 1:4 is used to feed the ridge gap waveguide and the slots. The power divided itself is fed with a waveguide transition. Detail design of the antenna is presented. The antenna has the impedance bandwidth of 9% at the center frequency of 38.5 GHz, The antenna gain is 21 dBi and the side lobe level is less than 12 dB.
12:10 Contactless Flange Adapters for Mm-Wave Measurements
Esperanza Alfonso, Simon Carlred, Stefan Carlsson and Lars-Inge Sjöqvist (Gapwaves AB, Gothenburg, Sweden)
In this paper leakage-free contactless flange adapters for mm-wave frequencies are presented. The adapters are compatible with standard rectangular waveguide flanges, covering the whole operational bandwidth of those. They are placed in between standard waveguides in order to avoid leakage at the joints between flange surfaces. Unlike standard flanges, the adapters are contactless, i.e., they do not require to be in good electrical contact when connected to the flange surfaces. Therefore, the use of fastening screws can be replaced by more practical ways of interconnection, e.g., magnets. In the end, the use of such adapters between standard waveguide flanges allows for faster, accurate and reliable mm-wave measurements.

#### CS13 Electromagnetic Methods for Direct and Inverse Scattering Involving Stratified Media

Radars / Convened Session / Propagation
Oral Sessions: Room 352A
Chairs: Matteo Pastorino (University of Genoa, Italy), Giuseppe Schettini (Roma Tre University, Italy)
08:40 Air-Launched and Ground-Coupled GPR Data
Nectaria Diamanti and A. Peter Annan (Sensors & Software Inc., Canada)
Ground penetrating radar (GPR) sees a wide range of applications; some investigations, such as assessment of roads and reinforced concrete bridge decks, often employ vehicle mounted GPRs. When mounted on vehicles, GPR can be deployed in an air-launched or ground-coupled form. The trade-offs in GPR performance are seldom discussed and not well understood for the two approaches of deployment. Further, what maximum height is acceptable for being ground-coupled and what is the minimum height to be considered air-launched? Our goal is to study the behaviour of direct air/ground and reflected waves as antennas are moved from being directly on ground to being in air (i.e., at a height off the air-ground interface, where the surface reflection is clearly isolated from the direct signal). We present both numerical simulation results and observed GPR data to study and characterize responses. Results confirm the generally observed behavior and provide insight into the trade-offs.
09:00 Antenna Design for Microwave Tomography Imaging of High Contrast Mediums
Samuel Poretti, Matteo Lanini, Andrea Salvadè, Manuela Maffongelli and Ricardo D. Monleone (University of Applied Sciences of Southern Switzerland, Switzerland)
A new multistatic microwave imaging system containing specially designed antennas to avoid strong reflections at the interface to material samples with high dielectric constant is presented. The structure consists of a switched antenna array put in direct contact with the material in analysis and able, thanks to the antenna design, to minimize the interface impedance mismatch.
09:20 Buried Object Detection and Imaging Through Innovative Processing of GPR Data
Marco Salucci (ELEDIA Research Center, Italy); Lorenza Tenuti (ELEDIA Research Center, University of Trento, Italy); Lorenzo Poli and Andrea Massa (University of Trento, Italy)
An innovative two-dimensional (2D) inverse scattering (IS) approach for processing Ground Penetrating Radar (GPR) data is presented to retrieve the electromagnetic characteristics of a buried domain. The developed GPR-IS approach exploits a multi-frequency (MF) strategy to deal with the wideband nature of the available measurements and a multi-resolution (MR) scheme to reduce the ratio between problem unknowns and informative data. Moreover, a customized Particle Swarm Optimizer (PSO) is exploited in order to overcome the limitations of deterministic approaches in finding the global optimum of the arising MF cost function, which is characterized by a high density of local minima (i.e., false solutions).
09:40 Direct Scattering Methods in Presence of Interfaces with Different Media
Cristina Ponti and Giuseppe Schettini (Roma Tre University, Italy)
Several techniques have been developed to solve the direct scattering problem from targets involving different media and interfaces. For the case of stratified media and embedded targets, different formulations based on integral equations solved with method of moments have been proposed. Time-domain methods have the advantage to return results in the form of radargrams typical of measurements with pulsed techniques. Among them, the Finite-Difference Time-Domain method is widely used due to its high flexibility in the simulation of targets and backgrounds of arbitrary shape. For the case of targets with canonical shape, i.e., circular cross-section cylinders, in a non-homogeneous background, the Cylindrical Wave Approach gives a semi-analytical solution that is fast and accurate.
10:00 Microwave Imaging of Non-weak Targets in Stratified Media via Virtual Experiments and Compressive Sensing
Roberta Palmeri (University of Reggio Calabria, Italy); Martina Teresa Bevacqua (University Mediterranea, Italy); Loreto Di Donato (University of Catania, Italy); Lorenzo Crocco (CNR - National Research Council of Italy, Italy); Tommaso Isernia (University of Reggio Calabria, Italy)
Tomographic approaches represent an emerging way to process GPR data and to investigate stratified media, since they allow to obtain images that are more readable than those achieved with standard data processing, which require human expertise and may show high probability of false alarms. In this contest, an efficient inverse scattering strategy is proposed to achieve dielectric characterization of buried objects in lossy and stratified soils. The approach exploits the framework of the "virtual scattering experiments" in a stratified media, thus allowing to deal with not only the non linearity of the underlying physical phenomena, but also to counteract the difficulty arising from the aspect limited measurement configuration adopted in GPR surveys. The proposed method is tested through a numerical example, by considering Compressive Sensing regularization scheme in order to enhance imaging resolution capabilities.
10:20 Coffee Break
10:50 Near-Field Focusing Technique for Enhanced Through-the-Wall Radar
Sandra Costanzo and Giuseppe Di Massa (University of Calabria, Italy)
The adoption of a Bessel beam source is proposed in this work as localized near-field antenna for through-the-wall radar applications. The basic idea is to exploit all appealing features of Bessel beams, in terms of ideally infinite propagation depth, narrow beam pattern and field invariance on the transverse plane, to enhance both the resolution as well as the robustness towards clutter effects of new generation through-the-wall systems.
11:10 Numerical Analysis of the Performance of a Multi-Frequency Inversion Scheme for Subsurface Prospection
Alessandro Fedeli, Matteo Pastorino and Andrea Randazzo (University of Genoa, Italy)
An analysis of the performance of a multi-frequency inverse-scattering algorithm for imaging of buried scenarios is reported in this paper. The considered inversion procedure is based on the use of a regularization scheme in the Lp Banach spaces able to solve the full non-linear half-space inverse scattering problem. The effects of different configurations of the soil are evaluated by means of numerical simulations.
11:30 Oblique Incidence Scattering by a Periodic Cylinder Array with Heterogeneous Cylinders
Koki Watanabe (Fukuoka Institute of Technology, Japan)
This paper deals with the electromagnetic scattering of a plane-wave obliquely incident on a periodic circular cylinder array including heterogeneous cylinders, and shows a spectral-domain formulation based on the recursive transition-matrix algorithm. Generally, the fields in imperfectly periodic structures have continuous spectra in the wavenumber space, and the spectral-domain approaches require an artificial discretization in the wavenumber space. The present formulation also uses a concept of the pseudo-periodic Fourier transform, and the discretization scheme can be considered only inside the Brillouin zone.
11:50 Buried Targets Detection from Synthetic and Measured B-scan Ground Penetrating Radar Data
Xiang Liu, Mohammed Serhir, Abelin Kameni, Marc Lambert and Lionel Pichon (GeePs- Group of electrical engineering, Paris)
The localization of buried targets using Ground Penetrating Radar (GPR) is dealt with. The bi-static GPR is made of two identical Vivaldi antennas operating from 0.5 GHZ to 3.5 GHz and installed in front of a sand box. The experimental data acquired in a controlled laboratory environment are validated by electromagnetic simulation. Then, both synthetic and experimental data are processed to detect the buried targets via three imaging methods. The targets localization is achieved from the GPR B-scan data. The results obtained via Stripmap SAR, Frequency-Wavenumber (F-K) migration and Kirchhoff migration are presented and compared.
12:10 High Capacity Imaging Using an Array of Compressive Reflector Antennas
Jose Martinez Lorenzo, Ali Molaei, Galia Ghazi and Juan Heredia-Juesas (Northeastern University, USA); Hipólito Gómez-Sousa (Northeastern University)
This paper presents a novel high sensing capacity compressive imaging system, which is capable of imaging human-size targets. The system uses an array of Compressive Reflector Antennas (CRAs) in order to extend the imaging domain of a single CRA. Moreover, the multi-static electromagnetic cross-coupling of adjacent CRAs in the array is used as a mechanism to improve the imaging performance. A physical optics method is used as a forward model; and the Total Variation norm option, in the NESTA software, is used for performing the compressive imaging. Preliminary results show that the system is capable of providing an accurate reconstruction of a tesselated model of a human body.

### Wednesday, March 22, 08:40 - 10:20

#### L_A03 MIMO & Smart Antennas

Localization & Connected Objects / Regular Session / Antennas
Oral Sessions: Room 352B
Chairs: Nima Jamaly (Swisscom, Switzerland), Mario Schühler (Fraunhofer Institute for Integrated Circuits IIS, Germany)
08:40 Large Dielectric Resonator Antenna ESPAR for Massive MIMO Systems
Reza Movahedinia (Concordia University, Montreal, Quebec H3G 1M8, Canada); Mohammad Reza Chaharmir (Communications Research Centre, Canada); Abdel R. Sebak and Ahmed Kishk (Concordia University, Canada)
A large array of dielectric resonator antenna (DRA) based on Electrically-Steerable Parasitic Array Radiator (ESPAR) concept is presented for massive MIMO application. The proposed array consists of 18 sub-arrays while each subarray has three single units. Each single antenna units consist of four driven DRA, coupled to the parasitic DRAs in their E- and H-Planes. All the antenna elements placed in an interleaved arrangement which surpass the grating lobes with better scanning capabilities in all azimuthal directions. With the beam scanning capability feature of each sub-array, the proposed array can be a good candidate for massive MIMO and mm-wave application.
09:00 Throughput Estimation for 2 x 2 MIMO System with Single Leaky Feeder Cable
Nima Jamaly, Damiano Scanferla and Hugo Lehmann (Swisscom, Switzerland)
The current paper deals with application of leaky feeder cables (LFCs) in linear-cells MIMO systems. We first revisit the method whereby we can map the measured channel data to throughput in an LTE system. Later we show that feeding an LFC from its both ends by two independent signals can potentially lead to a promising 2x2 MIMO system with a desirable throughput. Our results also interestingly demonstrate that feeding an LFC from both ends yields a constant average throughput all along the cable. However, the corresponding average throughput is dependent on the length of the cable and its longitudinal loss. For very long LFCs, the system may also convert to rank one system. We discuss about this case too.
09:20 On RSSI-Based Direction-of-Arrival Estimation Using Multibeam Antennas
Mario Schühler (Fraunhofer Institute for Integrated Circuits IIS, Germany); Lars Weisgerber and Burak Sahinbas (Fraunhofer IIS, Germany)
An approach for direction-of-arrival estimation is presented that relies on a multibeam antenna. The antenna provides a pre-defined set of radiation patterns with distinct main directions. The approach considers only magnitudes of a received signal after its decomposition by means of a beam-forming network. Its application to measured signals obtained from an experimental setup is discussed, revealing that the resolution of the direction estimated is not limited by the beamwidth of the radiation patterns.
09:40 AoA and Source Polarization Estimation with Circularly Polarized Multibeam Antenna Using MUSIC Algorithm
Burak Sahinbas and Lars Weisgerber (Fraunhofer IIS, Germany); Mario Schühler (Fraunhofer Institute for Integrated Circuits IIS, Germany)
The angle-of-arrival estimation algorithm MUSIC using a multibeam antenna was investigated. The antenna is composed of four circularly polarized antenna elements and a beam-forming network, which provides a switchable set of radiation patterns with distinct main lobe directions. Circularly polarized lobes are not affected from random source inclinations in terms of polarization losses. But they have a limited axial ratio beamwidth, being a limitation for direction finding algorithm based on phase difference. This limitation is illustrated and utilizing the MUSIC algorithm. Compensation of the effect of source inclination on the direction of arrival estimation with a multibeam antenna is presented.
10:00 Achieving Physical Layer Security with Massive MIMO Beamforming
Elias Yaacoub (Arab Open University, Lebanon); Mohammed Al-Husseini (Beirut Research and Innovation Center, Lebanon)
Physical layer security allows secure communications between a source and destination without the need to resort to key-based encryption techniques. Its increasing importance stems from the difficulty of implementing advanced encryption techniques in certain networks, such as the internet of things (IoT). In this paper, physical layer security is implemented by using massive multiple input multiple output (MIMO) techniques. Specifically, beamforming with large cylindrical antenna arrays is investigated. These arrays allow the transmission of both the useful signal to the destination and the jamming signal to the eavesdropper without resorting to the help of other nodes for relaying the signal and/or jamming the eavesdropper. Simulation results show that high levels of secrecy capacity can be achieved with the proposed approach.

#### CS10 Characteristic Mode Analysis for Platform-Mounted Antenna Design

Methods & Tools / Convened Session / Antennas
Oral Sessions: Room 353
Chairs: Yikai Chen (University of Electronic Science and Technology of China, P.R. China), Simone Genovesi (University of Pisa, Italy)
08:40 Aircraft Antenna Placement Using Characteristic Modes
Martin Vogel (Altair Engineering, USA); Willem J Strydom (Altair Development S.A. (Pty) Ltd, South Africa); Ulrich Jakobus (Altair Engineering GmbH, Germany); Peter Futter (Altair Development S.A. (Pty) Ltd, South Africa)
This paper illustrates the use of Characteristic Mode Analysis in FEKO to synthesize a desired combined antenna pattern of multiple antennas mounted on an aircraft, and to mitigate co-site interference between antennas on an aircraft.
09:00 Characteristic Mode Control Via Partial Coating of Reactive Components on Conducting Surfaces
Sai Ho Yeung and Chao-Fu Wang (National University of Singapore, Singapore)
Characteristic mode control via partial coating of reactive components on top of conducting surfaces will be investigated in this study. The objective of the research is to lower the resonant frequency of a particular characteristic mode that has the desired radiation pattern, and excite it for radiation. The control can be implemented by loading capacitive and inductive components on top of conducting surfaces. For demonstration purpose, capacitive components are coated on a conducting surface to lower the resonant frequency of a particular characteristic mode, which radiates along the horizontal plane.
09:20 Design of Vehicle-Mounted, Compact VHF Antennas Using Characteristic Mode Theory
Compact and low-profile VHF antennas with enhanced bandwidth have a wide spectrum of applications in both commercial and military communication systems. Having both of these criteria in a single antenna, however, is very challenging. In this paper, we demonstrate a method for bandwidth enhancement of vehicle-mounted electrically-small antennas operating in the VHF band. In this method, the vehicle platform is considered to be the major part of the radiating structure, while a meandered monopole antenna is used as a capacitive coupling element to excite a desired set of characteristic modes of the platform. The size of the coupling element is 0.06lambda x 0.06lambda x 0.06lambda, where lambda is the free-space wavelength at the frequency of operation, 60 MHz (ka = 0.47). The proposed approach was employed to successfully enhance the bandwidth of a vehicle-mounted VHF antennas by at least 400%.
09:40 Excitation of Multiple Characteristic Modes on a Three Dimensional Platform
Simone Genovesi (University of Pisa, Italy); Francesco Alessio Dicandia (Università di Pisa, Italy); Agostino Monorchio (University of Pisa & CNIT, Italy)
This work is a preliminary investigation of the possibility to excite a set of characteristic modes on a three dimensional object. The aim of this study is to provide guidelines for the excitation of characteristic modes on a complex platform in order to obtain a pattern reconfigurable.
10:00 HF Band Aircraft Integrated Multi-Antenna System Designs Using Characteristic Modes
Chenghui Wang and Yikai Chen (University of Electronic Science and Technology of China, P.R. China); Shiwen Yang (University of Electronic Science and Technology of China (UESTC), P.R. China)
In this paper, we present an approach to design conformal HF band multi-antenna system for aircraft using the characteristic mode theory. The whole antenna system generates omni-directional radiation pattern at 18 MHz, NVIS radiation pattern at 8 MHz and downward radiation pattern at 28 MHz. The antenna system is realized by a pair of folded monopole exciters embedded on the vertical stabilizers, a pair of probes to excite the long notches cut in the vertical stabilizers, and a pair of folded monopole exciters embedded on the horizontal stabilizers, respectively. Properly designed matching networks are used to match the input impedance of these exciters. The simulated input impedance bandwidth of the three antennas are 1.6%, 7.6%, and 12.5%, respectively. The port isolation is more than 10 dB across the whole interested frequency band.

#### Sp_P02 Tropospheric Propagation for Space Applications II

Space / Regular Session / Propagation
Oral Sessions: Room 362/363
Chairs: Lorenzo Luini (Politecnico di Milano, Italy), Michael Schönhuber (Joanneum Research, Austria)
08:40 Improving Weather-Forecast Based Model Chain to Optimize Data-Volume Transfer for Ka-band Deep-Space Downlinks
Marianna Biscarini, Frank S. Marzano and Luca Milani (Sapienza University of Rome, Italy); Mario Montopoli (ISAC CNR, Italy); Klaide De Sanctis (HIMET, Italy); Saverio Di Fabio (CETEMPS, Italy); Domenico Cimini (IMAA-CNR & CETEMPS University of L'Aquila, Italy); Maria Montagna (SciSys @ ESA, Germany); Mattia Mercolino and Marco Lanucara (European Space Agency, Germany)
In this work, we expose the fine-tuning and validation processes (based on radiometric and radiosounding measurements) of a preiously developed WF-based technique. The latter is a model chain that exploits weather forecasts (WF) for the optimization of deep-space satellite downlink at Ka-band. The presented results confirm the reliability of the WF-based technique and its better performances with respect to more traditional techniques. In terms of yearly-received data-volume, we have found a gain of about 15% to 24% associated with a decrease of the yearly lost data. These results make the proposed WF-based technique actually suitable for planning deep-space satellite-transmissions at Ka-band.
09:00 About Seasonal Variations of Specific Attenuations Derived from DSD Measurements
Michael Schönhuber, Jesus Peña Mateos and Karin Plimon (Joanneum Research, Austria)
Reliable estimates of satellite channel characteristics are of great importance for satellite communications, especially with use of even higher frequencies as Ka-band and in near future Q- and V-band. At a given rain rate the shape of rain drop size distributions (DSDs) considerably influences the corresponding specific attenuation. In previous work it was shown, that annual DSD statistics give evidence for geographical dependence. In this paper first results indicate that the seasonal variations of the DSD shapes are minor in comparison to the geographical dependencies. This points to a conclusion that a global map of annual DSD statistics will give a valuable contribution to satellite link parameter estimates.
09:20 Improved Scaling Factor for Long-Term Rain Attenuation Statistics as a Function of Link Elevation
Luciano M Tomaz (Politecnico di Milano); Carlo Capsoni and Lorenzo Luini (Politecnico di Milano, Italy)
The attenuation due to rain is one of the main impairments in satellite communications. It is well known that rain attenuation is dependent on the elevation angle of the link, being more severe at low elevation angles; this has a definite impact on the design of TLC and data download systems based on LEO satellites. This paper presents a simple model to scale long-term rain attenuation statistics as a function of link elevation angle. The model receives as input the known complementary cumulative distribution (CCDF) at a specific elevation and generates the CCDF scaled at other elevation angles.
09:40 Statistics of Attenuation Due to Rain Affecting Hybrid FSO/RF Link: Application for 5G Networks
Umair Ahmed Korai (University of Strathclyde, United Kingdom (Great Britain) & IICT, Mehran University of Engineering and Technology, Jamshoro, Pakistan); Lorenzo Luini (Politecnico di Milano, Italy); Roberto Nebuloni (Ieiit - Cnr, Italy); Ivan Glesk (University of Strathclyde, United Kingdom (Great Britain))
This paper shows that FSO could be an option for backhauling among microcells in future 5G systems in areas where fog is not a concern as very short LOS links (few hundred meters) would be required. In this respect, monthly CCDFs of rain attenuation at both RF (28 GHz) and optical bandwidth have been calculated in the area of Hyderabad (Pakistan). FSO links with simple OOK modulation would be able to reach targeted data rate of hundreds of Gbps for 99.99% of time provided the link length is less than few hundreds of meters
10:00 Impact of Rain Attenuation on 5G Millimeter Wave Communication Systems in Equatorial Malaysia Investigated Through Disdrometer Data
Hong Yin Lam (Universiti Tun Hussein Onn Malaysia, Malaysia); Lorenzo Luini (Politecnico di Milano, Italy); Jafri Din and Manhal Jaafar Alhilali (Universiti Teknologi Malaysia, Malaysia); Siat Ling Jong (Universiti Tun Hussein Onn Malaysia, Malaysia); Félix Cuervo (Joanneum Research, Austria)
Next-generation 5G cellular networks are expected to operate on the millimeter wavelength frequencies (e.g., 28 GHz and 38 GHz) to offer broader bandwidths and higher data rates. In this frequency band, rain is a major impairment to received signal power. This work aims to improve predictions of rain attenuation for 5G wireless networks operating at 28 GHz and 38 GHz in heavy rain regions, by exploiting three years of raindrop size distribution data collected at Kuala Lumpur (Malaysia). The specific attenuation is calculated by means of point matching technique and each minute of DSD data. The empirical relationship between specific attenuation and rainfall intensity are subsequently derived and compared with those for Rec. ITU-R P.838-3 and Singapore results. The results indicate substantial local deviations from the ITU-R model, especially at 38 GHz. These results offer important information for predicting rain attenuation of 5G wireless communication systems in heavy rain regions.

### Wednesday, March 22, 08:40 - 12:30

#### SWS_05: Revision and Changes to the IEEE 149 Standard on Antenna Measurements (AMTA Workshop)

WG Meetings & WorkShops: Room 315
Chairs: Lars Foged (Microwave Vision Italy, Italy), Manuel Sierra-Castañer (Universidad Politécnica de Madrid, Spain)

### Wednesday, March 22, 10:50 - 12:30

#### C_P04 Millimeter Wave Radio Channels II

Cellular Communications / Regular Session / Propagation
Oral Sessions: Room 342A
Chairs: Reiner S. Thomä (Ilmenau University of Technology, Germany), Jianyao Zhao (Huawei Technologies Co., Ltd., P.R. China)
10:50 Millimeter-Wave Outdoor-to-Indoor Channel Measurements at 3, 10, 17 and 60 GHz
Cheikh Diakhate (Telecom ParisTech, Université Paris-Saclay & Orange Labs, France); Jean-Marc Conrat (Orange Labs, France); Jean Cristophe Cousin (Ecole Nationale Supérieure de Télécommunications, France); Alain Sibille (Telecom ParisTech, France)
Millimeter-Wave (mmW) communication systems, capable of achieving high data rates thanks to the large bandwidth available in this frequency range, are a promising 5G technology. Studies in this paper investigate the radio propagation channel at 3, 10, 17 and 60 GHz in an Outdoor-to-Indoor (O2I) scenario. Measurements were conducted using a wideband channel sounder to derive channel parameters such as building penetration losses and channel delay spread values. It was observed that signal attenuation is strongly material-dependent and also, to some extent, frequency-dependent as well. However, the delay spread is weakly correlated with the frequency.
11:10 A 32 GHz Urban Micro Cell Measurement Campaign for 5G Candidate Spectrum Region
Mamadou Dialounke Balde (University of Rennes 1, France); Joni Vehmas, Sinh Nguyen and Katsuyuki Haneda (Aalto University, Finland); Heykel Houas (ANFR); Bernard Uguen (University of Rennes I, France)
A 32 GHz Urban Micro cell (UMi) measurement campaign is presented in this paper. A path loss model in line of sight (LOS) for the 5G frequency band 31.8-33.4 GHz is provided and different classical key channel metrics are investigated. Furthermore, we corroborate that no significant difference is noted between the 28 GHz and 32 GHz frequency bands with respect to the main channel characteristics.
11:30 28 GHz Millimeter-Wave Measurements and Models for Signal Attenuation in Vegetated Areas
Junghoon Ko (Korea Advanced Institute of Science and Technology (KAIST), Korea); Yun-Seok Noh and Yong-Chan Kim (KAIST, Korea); Sooyoung Hur (Samsung Electronics Co., Korea); Sung-Rok Yoon (Samsung Electronics, Korea); DongHyuck Park and Kuyeon Whang (Samsung Electronics Co., Korea); Dong-Jo Park and Dong-Ho Cho (Korea Advanced Institute of Science and Technology, Korea)
This paper presents 28 GHz channel measurements in vegetated areas using a directional channel sounder. The measurement campaign was conducted for two different scenarios on the campus of Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, South Korea. It is found that the excess loss in vegetated areas shows a saturating trend at 28 GHz. From the measurement results, we presented 28 GHz foliage propagation models which are based on the ITU-R terrestrial model and the FITU-R-like frequency-dependent model. The average RMSE values between the measurements and the two considered models for scenario 1 were 3.09 and 3.51 dB, respectively, while the average RMSE values for scenario 2 were 4.58 and 4.39 dB, respectively. In addition, the proposed models were compared with some existing attenuation models which are applicable at 28 GHz. These results can be used in predicting path loss through vegetated areas at 28 GHz.
11:50 On the Stochastic and Deterministic Behavior of mmWave Channels
Naveed Iqbal (Huawei Technologies, Germany); Christian Schneider (Ilmenau University of Technology, Germany); Jian Luo (Huawei Technologies Duesseldorf GmbH, Germany); Diego Dupleich (Ilmenau University of Technology, Germany); Robert Müller (TU Ilmenau, Germany); Stephan Haefner (Technische Universität Ilmenau, Germany); Reiner S. Thomä (Ilmenau University of Technology, Germany)
A wireless channel is always composed of both deterministic and stochastic multi-path components. A high Rician K-factor increases the contribution of deterministic channel components, thereby reducing the significance of stochastic parts of a channel. This paper focus at the investigative analysis of fading depth and K-factor to analyze the deterministic behavior of a channel under a certain bandwidth and propagation setup. It has been observed that small scale fading depth asymptotically converges towards zero dB whereby K-factor increases with bandwidth. Results also show that the de-polarization of a signal increases its amplitude fading. This effect is much more significant at lower bandwidths but an increase in bandwidth reduces the difference in fade depths between polarized and depolarized signals. These observations lead to a conclusion that channel tend to be more deterministic at higher bandwidths.
12:10 Height-dependent Path Loss Model and Large-Scale Characteristics Analysis of 28 GHz and 38.6 GHz in Urban Micro Scenarios
Zhimeng Zhong, Chao Li and Jianyao Zhao (Huawei Technologies Co., Ltd., P.R. China); Xiaomei Zhang (Huawei, P.R. China)
In this paper, by equipping with omni-directional antennas and high gain power amplifier in our channel sounder system, the propagation characteristics which de-embed antenna response at 28GHz and 38.6 GHz are analyzed. The base station height-dependent path loss model is derived by the channel measurement in non-line-of-sight (NLOS) urban micro outdoor scenarios. Furthermore, the path loss models at 28G and 38.6G Hz are compared with the path loss model at 3.5G. Also，the proposed path loss model is compared with 3GPP 38.900 path loss model, and it can be found that 3GPP will overestimate the system performance since the 3GPP model has lower path loss. Finally, some preliminary research on the shadowing effect of human body and vegetation are presented.

#### B_M01 Biological Measurements

Biomedical / Regular Session / Measurements
Oral Sessions: Room 342B
Chairs: Robin Augustine (Uppsala University, Sweden), Ana L Neves (Institut Fresnel Centre Commun de Resources en Microondes, France)
10:50 A Simple Approach Towards a Multi-Frequency MRI Head Phantom
Ana L Neves (Institut Fresnel Centre Commun de Resources en Microondes, France); Lisa Leroi (Neurospin - CEA Saclay - Paris-Saclay University, France); Nicolas Cochinaire (Institut Fresnel, France); Redha Abdeddaim (Aix Marseille University, France); Pierre Sabouroux Pierre Sabouroux (Institut Fresnel, France); Alexandre Vignaud (Commissariat à l'Energie Atomique & NeuroSpin, France)
An anatomically realistic human head phantom was elaborated for different Larmor frequencies, which allows rapid quantification of B1+ of MRIs of different magnetic fields. The permittivity ε' and conductivity σ of sucrose/salt/agar aqueous solutions of varying concentration was determined; a solution with these components and having the adequate concentration to obtain the brain's dielectric properties at 3 T, 7T and 11.7T was manufactured. An anthropomorphic polymeric skull was filled with this mixture. To check the behavior of this phantom in a MRI configuration, both numerical and experimental validations were done: a B1+ field distribution inside the phantom was calculated with CST Microwave Studio inside a birdcage coil at 7T; the same mapping was assessed in a 7T MRI. This work has shown the possibility of manufacturing a head phantom with accessible and cheap components for MRI evaluation, having an adequate B1+ field distribution and the dielectric properties of the brain
11:10 Signal Analysis and Phantom Experiments for a Miniaturized Time-Domain Microwave Breast Health Monitoring Device
Karim El Hallaoui (McGill University, Canada); Adam Santorelli (National University of Ireland, Galway, Canada); Milica Popović and Mark Coates (McGill University, Canada)
This work presents a miniaturized system for performing time-domain microwave scans to detect malignancies within breast tissue. The proposed changes miniaturize components of the system designed by the McGill Breast Cancer Detection Group. The aim of this paper is to present the implementation of the Adafruit Si5351 Clock Generator and the Furaxa Pulser as an alternative to the currently used large table-top and expensive Tektronix gigaBERT 1400 Clock Generator and Picosecond Model 3600 Impulse Generator respectively. The miniaturized and cost-effective components can be integrated to achieve a comfortable and compact medical imaging device. This paper validates the proposed changes to the system by comparing their signals at the relevant stages of the system. Moreover, a dataset is collected with the proposed system changes using realistic breast phantoms across a five day period.
11:30 Link Budget Study and Realization of Time-Domain Measurement Setup for Implantable Antennas
Joao Felicio (Instituto de Telecomunicações/Instituto Superior Técnico, Portugal); Carlos A. Fernandes (Instituto de Telecomunicacoes, Instituto Superior Tecnico, Portugal); Jorge R. Costa (Instituto de Telecomunicações / ISCTE-IUL, Portugal)
This paper extends the study of a previously proposed wideband implantable antenna to be embedded at superficial level in the muscle. The antenna covers the frequency band between 1.4 GHz and 4.2 GHz and is compatible with integration with an energy scavenging circuit. We assess its performance through a time-domain setup and emphasize some aspects regarding the measurements. Finally, we perform a complete study of the link budget between the passive implant and the external reader that supplies the energy for powering the implant assuming European regulation.
11:50 Microwave Sensors for New Approach in Monitoring Hip Fracture Healing
Mauricio D Perez (Uppsala University, Sweden & National Technological University, Argentina); Syaiful Redzwan Mohd Shah and Jacob Velander (Uppsala University, Sweden); Marco Raaben (University Medical Center Utrecht, The Netherlands); Noor Badariah Asan (Uppsala University, Sweden & FKEKK, Universiti Teknikal Malaysia Melaka, Malaysia); Taco Blokhuis (University Medical Center Maastricht, The Netherlands); Robin Augustine (Uppsala University, Sweden)
Cyber-Physical System (CPS) applications in lower-extremity bony-fracture rehabilitation systems require real-time biophysical data. Emerging and interesting solutions are microwave approaches that provides good contrast between hard and soft tissues and between local anomalies inside tissues. Preliminarily some contacting non-invasive planar methods have been investigated in their feasibility of detecting human tissues variations with promising results. In this work we introduce two new microwave planar sensors for a new approach of hip fracture healing follow-up tool. They are designed for improved resolution and penetration at frequencies between 1 to 3 GHz in detecting variations in bone, muscle or fat tissues that are expected during a rehabilitation process. The resonant devices are optimized using Frequency Domain Reflectometry and CST® environment and validated using clinical trials with volunteers. The new approach is validated using clinical trials with volunteers and patients. These outcomes emphasize the feasibility of devising systems for hip after-fracture rehabilitation.
12:10 Microfluidic Planar Resonator Sensor with Highly Precise Measurement for Microwave Applications
Amyrul Azuan Mohd Bahar, Zahriladha Zakaria, Siti Rosmaniza Ab Rashid and Azmi Awang Md Isa (Universiti Teknikal Malaysia Melaka, Malaysia); Rammah A. Alahnomi (Universiti Teknikal Malaysia Melaka (UTeM), Malaysia); Yosza Dasril (Universiti Teknikal Malaysia Melaka, Malaysia)
In this paper, a microfluidic planar resonator sensor is proposed to identify the unknown permittivity of liquid solvents. The frequency response from known permittivity of solvents is critically analyzed using polynomial plotting graphs. Meanwhile, high sensitivity detection sensor with more than 400 quality factor and 0.27% maximum discrepancy errors is observed. The proposed planar resonator was designed, fabricated, and validated. Both simulated and measured results are in good agreement and it is suitable for pharmaceutical and biomedical applications.

#### L_P01 Localization & Ranging

Localization & Connected Objects / Regular Session / Propagation
Oral Sessions: Room 352B
Chairs: Wout Joseph (Ghent University/IMEC, Belgium), Yang Miao (Catholique Universite de Louvain, Belgium)
10:50 A Propagation Modeling Approach to Urban Navigation
Zhuangzhuang Dai, Robert J Watson and Peter Shepherd (University of Bath, United Kingdom (Great Britain))
The performance of GPS in densely built urban areas is greatly undermined due to multipath propagation. Therefore, we propose a propagation model which is used to obtain 'location fingerprints' with the aid of modern computers thanks to their growing processing power. At the heart of the technique is the use of a ray-launching model from which a database is generated containing propagation parameters such as received signal strength, time of arrival and angle of arrival as a function of source and receiver location. These are then mapped with physical locations using an artificial neural network. Besides, a sequence based tracking tool is proposed to assist navigation with minimal communication required between mobile device and database. This paper details the generation of a database for real world geometries read from OpenStreetMap and the development of a localisation algorithm.
11:10 Efficient Time Domain HF Geolocation Using Multiple Distributed Receivers
Ankit Jain (IMT Atlantique, France); Pascal Pagani and Rolland Fleury (Telecom Bretagne, France); Michel Ney (TELECOM Bretagne Institute, France); Patrice Pajusco (TELECOM Bretagne, France)
This paper explores the effect of increasing number of receivers to evaluate the geographic location of the High Frequency (HF) transmitters for distances in the radius of 2000 km. In the case of HF propagation over long distances, signals propagate using skywaves and are reflected back to the earth from the ionosphere. The Quasi-Parabolic (QP) model of the ionosphere provides analytic equations for ray path parameters through which the signal travel time is obtained. The position of the transmitter is found using time domain HF geolocation method namely Time Difference of Arrival (TDoA). An analysis of the QP model of the ionosphere is provided and limits of the model are emphasized. The geolocation algorithm for TDoA along with its mathematical equation is explained. Simulation results demonstrate that increasing the number of receivers leads to a significant improvement in the geolocation accuracy.
11:30 Radio Frequency UAV Attitude Estimation Using Direction of Arrival and Polarization
Attiya Mahmood (Brigham Young University, USA); Jon Wallace (Lafayette College, USA); Michael Jensen (Brigham Young University, USA)
This paper proposes a new algorithm for estimating the relative attitude between two unmanned aerial vehicles based on multiple-input multiple-output radio frequency transmissions between the two aircraft. The method is able to estimate all three Euler angles required to describe the relative attitude, in contrast to prior methods that place severe limits on what can be estimated. Initial simulations based on the algorithm reveal that the estimation errors are relatively small even for moderate signal-to-noise ratios.
11:50 Long Reading Range Chipless RFID System Based on Reflectarray Antennas
Maher Khaliel (Universität Duisburg-Essen, Germany); Ahmed El-Awamry (University of Duisburg-Essen, Germany); Abdelfattah Fawky (University of Duisburg Essen, Germany); Thomas Kaiser (Universität Duisburg-Essen, Germany)
This work proposes the utilization of the Reflect Array (RA) antenna in the reader of the Frequency Coded (FC) chipless RFID systems aiming at increasing the reading range, minimizing the environmental reflections and acquiring a lot of novel capabilities that can not be provided by the conventional antenna systems. The presented RA antenna operates over UWB range of frequencies from 4 to 6 GHz fulfilling the requirements of the FC chipless RFID systems. Furthermore, the RA antenna beam is 4 times narrower than the feeder beam and thus 6 dB higher in gain with -10 dB SLL. Therefore, this developed UWB RA antenna is successfully integrated with the FC chipless RFID tags and a reading range of 1 m is attained. To the best of the author knowledge, this is the highest reading range achieved in the FC chipless RFID systems, considering real-world indoor environment and software defined radio reader.
12:10 Improved Energy Detection Receiver for Ranging in IEEE 802.15.4a Standard
Abdelmadjid Maali (Ecole Militaire Polytechnique, BEB, Alger, Algeria); Geneviève B. Baudoin (ESIEE, France); Mesloub Ammar (Ecole Militaire Polytechnique)
In this paper, we propose a novel energy detection (ED) receiver architecture combined with time-of-arrival (TOA) estimation algorithm, compliant to the IEEE 802.15.4a standard. The architecture is based on double overlapping integrators and a sliding correlator. It exploits a series of ternary preamble sequences with perfect autocorrelation property. This property ensures coding gain which allows an accurate estimation of power delay profile (PDP). To improve TOA estimation, the interpolation of PDP samples is proposed and the architecture is validated by using an ultra-wideband (UWB) signals measurements platform. These measurements are carried out in line-of-sight (LOS) multipath environment. The experimental results show that the ranging performances obtained by the proposed architecture are higher than those obtained by the conventional architecture based on a single-integrator.

#### B_P02 Body-Centric Propagation

Biomedical / Regular Session / Propagation
Oral Sessions: Room 353
Chairs: Luca Petrillo (Université Libre de Bruxelles, Belgium), Guido Valerio (Sorbonne Universités UPMC, France)
10:50 Power Coupling for Conceptual Antennas in Medical Implant Applications
Ali Khaleghi (Oslo University Hospital, Norway); Ilangko Balasingham (Norwegian University of Science & Technology & Oslo University Hospital, Norway)
In this paper, we study two conceptual antennas of loop and dipole geometries for power coupling in medical implant applications. The coupling between the on-body mounted antenna and the implant antenna is the study scenarios. A sample muscle tissue with the implant antenna of size 40 mm in the depth of 50 mm and wide frequency range of 200-3000 MHz are used for computations. Frequency dependent electromagnetic characteristics of the biological tissue are considered. It is shown, that the coupling between a pair of the loop antennas surpasses the coupling in the other combinations of the loop and dipole for the frequencies below 800 MHz. Also, the on-body loop antenna induces less specific absorption rate (SAR) than the dipole that permits more power injection and thus higher energy transfer to the implant antenna. Furthermore, the size effects of the loop antenna on the power coupling are reported.
11:10 Human Body Communication Channel Modeling Using Vector Network Analyzer Measurement
Luca Petrillo (Université Libre de Bruxelles, Belgium); Julien Sarrazin (University of Pierre & Marie Curie UPMC, France); Hugues Libotte (Université Libre de Bruxelles, Belgium); Aziz Benlarbi-Delaï (Sorbonne Universités, UPMC Paris 06, France); François Horlin (Université libre de Bruxelles, Belgium); Philippe De Doncker (ULB, Belgium)
Several studies have examined the propagation losses of the Human Body Communication (HBC) channel. However, a general agreement has not be found yet. In this paper, the complete S-matrix of the HBC channel is measured on an human subject using two kinds of electrode devices. The data is integrated in a lumped element model, which allows to take into account for the capacitive return path of realistic battery operated transmitter and receiver. Results, shown as power gain curves between 10 MHz and 150 MHz, exhibit a band pass profile, with cut-off frequency depending on the kind of electrode devices. A model is obtained by vector fitting of the equivalent Z-matrix of the measured HBC channel.
11:30 Implementation Methodology of Handshaking Communication Using Wearable Near-Field Coupling Transceivers
Ryo Takeuchi and Shin Hasegawa (Kyoto Institute of Technology, Japan); Yuichi Kado (Kyoto Institute of Technology & Graduate School of Science and Technology, Japan); Daiki Ayuzawa and Mitsuru Shinagawa (Hosei University, Japan); Kyoji Ohashi and Daisuke Saito (Nippon Signal Co., Ltd., Japan)
Near-field coupling communication (NFCC) is a communication technology that treats the surface of the human body as a transmission path by using a carrier frequency below 10 MHz. Because the radiation signal to a space is suppressed in NFCC, humans wearing an NFCC transceiver (TRX) can exchange personal information through handshaking without having to worry about information leakage. To establish stable personal information exchange, handshaking communication needs to satisfy two requirements relating to the signal propagation loss difference between standing and handshaking postures and the S/N ratio in the handshaking posture. From the equivalent circuit of the handshaking communication, we present the position of the TRXs that satisfy the two requirements. Experimental results revealed that the two requirements are satisfied when NFCC TRXs are inserted into the soles of shoes. As a result, we demonstrated that handshaking communication can be implemented by inserting TRXs into the soles of shoes.
11:50 Wavelet-Based Analysis of 60 GHz Doppler Radar for Non-stationary Vital Sign Monitoring
Ting Zhang (Sorbonne Universités, UPMC Paris 06, France); Guido Valerio (Sorbonne Universités UPMC, France); Julien Sarrazin (University of Pierre & Marie Curie UPMC, France); Mircea Dan Istrate (UTC, France)
We propose here a Doppler-radar implementation at 60 GHz for contactless monitoring of vital signs (respiration and heartbeat). In order to provide a real-time detection of non-stationary vital signs and critical events, an estimation technique is here used by means of a wavelet transform of the received signals. Moreover, the amplitudes of the relevant vital movements can be deduced by the wavelet transform so as to distinguish the useful signal from noises and non-desired movements.
12:10 An Application of Universal Polynomial Chaos Expansion to Numerical Stochastic Simulations of an UWB EM Wave Propagation
Piotr Górniak (Poznań University of Technology, Poland)
In the paper a new form of universal polynomial chaos expansion, which was introduced in [1], is applied to numerical stochastic simulations o ultra-wideband (UWB) electromagnetic wave propagation. It is assumed that stochastic parameters of a propagation scenario follow a Gauss distribution. The coefficients of an expansion are analytical functions of a mean and a standard deviation a stochastic variable (scenario parameter), which makes an expansion universal. The necessary initial coefficients have to be calculated numerically only once for a freely chosen values of stochastic variable parameters. Then these initial coefficients are used to calculate analytically the universal coefficient

#### Sp_A05 Antenna-System for Space Applications

Space / Regular Session / Antennas
Oral Sessions: Room 362/363
Chairs: Cecilia Cappellin (TICRA, Denmark), Chi-Chih Chen (The Ohio State University, USA)
10:50 A 6-40 GHz CubeSAT Antenna System
Jiukun Che (the Ohio State University, USA); Chi-Chih Chen and Joel T. Johnson (The Ohio State University, USA)
This paper presents a high-gain 6-40 GHz circularly polarized antenna system designed for a 6U CubeSAT mission for monitoring RF emission from earth. The antenna system consists of three quasi-tapered helical antenna elements, operating at 6-11 GHz, 11-22 GHz and 21-40 GHz, respectively. Each antenna element is designed to produce an end-fire beam with its helical diameter varying along its axis to achieve a linearly increasing gain from 12 dBic gain at 6 GHz to 20 dBic at 40 GHz. The close proximity of the antennas causes strong mutual coupling and pattern distortion. This problem is alleviated by carefully arranging the antenna positions, the utilization of different circular polarization (CP) handedness, as well as loading of the radome.
11:10 The Observable Field for Antennas in Reception
Andrea Neto, Nuria LLombart and Arturo Fiorellini Bernardis (Delft University of Technology, The Netherlands); Angelo Freni (University of Florence, Italy)
In this paper we provide a simple and accurate physical picture of the antenna reception mechanism. Specifically we introduce the concept of the observable field. This is the portion of the incident field that can be received by an ideal antenna located in a given region of space. Thus this field defines the available power, and provides clear guidelines into the design of such ideal antenna. The observable field is composed by two complementary inward and outward propagating spherical waves whose amplitude can be calculated, without introducing spherical wave vector modes, simply via the equivalence theorem. This methodology is derived here for a single plane wave but it can be easily extended to multiple coherent plane waves.
11:30 Full-Wave and Multi-GTD Analysis of the Ice Cloud Imager for MetOp-SG
Jakob Rosenkrantz de Lasson, Cecilia Cappellin and Per Nielsen (TICRA, Denmark); David Marote Alvarez, Marc Bergada and Raquel Gonzalez (Airbus/CASA, Spain); Peter de Maagt (European Space Agency, The Netherlands)
We report an RF study at 50 GHz of the Ice Cloud Imager, consisting of a parabolic reflector inside a semi-closed sun shield, as obtained with full-wave method of moments (MoM) and the asymptotic high-frequency multi-geometrical theory of diffraction (Multi-GTD) method. The Multi-GTD results accurately reproduce details of the main beam and sidelobes originating from focusing, but fail to predict other parts of the pattern that are due to a large number of scattering events inside the semi-closed sun shield. MoM results at the half and double frequency (25 and 100 GHz) show that the parts of the pattern that are not well described by Multi-GTD, but still within the dynamic MoM range, remain at the same overall level as the frequency is varied. Thus, when analyzing at higher frequencies of interest (> 183 GHz), a complementary MoM and Multi-GTD approach can be adopted to predict the radiation pattern.
11:50 A Dual-Band Wide-Angle Scanning Phased Array Antenna in K/Ka Bands for Satellite-on-the-Move Applications
Kamil Yavuz Kapusuz (Ghent University, Belgium); Ozlem Aydin Civi (Middle East Technical University, Turkey); Alexander Yarovoy (TU Delft, The Netherlands)
This paper presents the design of a dual-band cavity-backed phased array antenna with wide-angle scanning capability in K/Ka bands for the geostationary (GSO)-fixed satellite service (FSS). A planar radiating aperture-fed microstrip antenna is used to guarantee the low profile of the proposed element. To reduce the losses and mutual coupling, a novel antenna element similar to the cavity-backed Strip-Slot-Air-Inverted Patch (SSAIP) is proposed as an element of designed array of 81 elements. Wide-angle scanning up to 60o is achieved at both frequency bands of the operation.
12:10 A TM01 to TE11 Mode Converter Designed with Semicircular Waveguide Sections
Ashish Chittora (Pandit Deendayal Petroleum University, India); Sandeep Singh (Bhabha Atomic Research Centre, India); Archana Sharma (BARC, India); Jayanta Mukherjee (Indian Institute of technology Bombay)
A novel TM01 to TE11 mode converter with aligned ports, wide bandwidth and high conversion efficiency is proposed. Mode conversion is performed with a circular waveguide partitioned into two semicircular sections with different path length. Lower semicircular section has a cosine profile to provide a path difference of lambda_g/2 for the mode conversion. Mode converter was designed and simulated at 3 GHz operating frequency. Electric field calculation shows that the mode converter can handle up to 3 GW high power microwave pulse signal. The mode converter was fabricated and the mode conversion was verified experimentally, by measuring far-field radiation pattern of the output mode. The proposed mode converter has a symmetric structure and has the advantage of aligned ports and wide bandwidth.

### Wednesday, March 22, 13:30 - 15:00

#### Poster_03

Localization & Connected Objects / Regular Session / Antennas
Room: Poster Sessions: Corridor Neuilly
Chairs: Marjorie Grzeskowiak (University of Paris-Est Marne-la-Vallée, France), Patrick McEvoy (Dublin Institute of Technology, Ireland)
Analysis of Antennas for Underwater Applications
Andrea Massaccesi and Paola Pirinoli (Politecnico di Torino, Italy)
Underwater Communication has a wide range of applications. In the case of a short-range communication system, the use of electromagnetic waves has been recently proposed as an alternative to the mostly used acoustic waves. The design of the antennas to be used for underwater communication is strongly influenced by the electromagnetic properties of the water and therefore, after its design but before its experimental characterization, it is necessary to perform an accurate numerical analysis of its behavior. As a proof-of concept, here the results obtained with the full-wave numerical analysis of antennas designed for an underwater communication system between scuba divers are illustrated, considering two types of realistic water environment: seawater and freshwater.
Design of a Dual-mode Meander-line Loaded Monopole Antenna with Characteristic Mode Theory
Mohammad Bagheriasl (University of Tehran, Iran); Karim Mohammadpour-Aghdam (University of Tehran & KUL, Iran); Reza Faraji-Dana (Center of Excellence on Applied Electromagnetic Systems, Iran)
The authors have previously proposed a tunable meander-line loaded monopole antenna. In this paper, the antenna structure proposed by the authors is modified to operate as a dual-mode antenna with very good frequency bandwidth. Characteristic mode analysis is performed on the modified antenna structure to investigate the suitability of the novel structure for dual-mode operation. Then, a dual-mode antenna is designed and the performance of such antenna is investigated.
Equivalent Input and Output Impedances in HF RFID System Including Resonator
Benamara Megdouda (University Paris Est Marne La Vallee, France); Marjorie Grzeskowiak (University of Paris-Est Marne-la-Vallée, France); Antoine M Diet (Paris Saclay - Université Paris Sud ( GeePs UMR 8507 - IUT de Cachan ), France); Gaelle Lissorgues (ESIEE, France); Yann Le Bihan (LGEP UMR 8507, France)
High Frequency Radio Frequency Identification (HF RFID) system based on Magnetically Coupled Reader Resonator Coils (MCRRC) is reported. The proposed system consists of reader antenna including small resonant coil operating by magnetic coupling with the tag coil. In the proposed system, the reader and tag impedances are modified. The equivalent electrical model is used to express the equivalent impedance matrix and used to express the equivalent input and output impedances of the system. The formulas are confirmed by comparison between High Frequency Structure Simulator (HFSS) results and measures.
Coaxially Distributed Diameter sub-Coil Twisted Loop Antenna in HF RFID
Marjorie Grzeskowiak (University of Paris-Est Marne-la-Vallée, France); Antoine M Diet (Paris Saclay - Université Paris Sud ( GeePs UMR 8507 - IUT de Cachan ), France); Benamara Megdouda (University Paris Est Marne La Vallee, France); Stephane Protat (University of Paris-Est Marne-la-Vallée, France); Christophe Conessa (GeePs/CentraleSupélec/CNRS, France); Marc Biancheri-Astier (Paris Saclay - Université Paris Sud ( GeePs UMR 8507 - IUT de Cachan ), France); Francisco Alves and Yann Le Bihan (GEEPS, France); Gaelle Lissorgues (ESIEE, France)
This paper proposes an HF (High Frequency) transmitting coil less sensitive to the angular and position misalignments of the small receiving coil. The DDC (Distributed Diameter Coil) shape and TLA (Twisted Loop Antenna) allow respectively minimizing the disturbance of the magnetic link due to the lateral misalignment and the relative tilting direction of the transmitting coil to the receiving coil. The magnetic coupling link obtained from DDC TLA coils is illustrated by comparison with conventional TLA in the case of HF RFID.
Low-Cost Surrogate Modeling for Rapid Design Optimization of Antenna Structures
Slawomir Koziel (Reykjavik University, Iceland); Adrian Bekasiewicz (Gdansk University of Technology, Poland)
Availability of fast yet reliable replacement models is essential to reduce the computational cost of antenna design process. Unfortunately, conventional approximation (or data-driven) modeling is not well suited for modeling of highly nonlinear responses of antenna structures, especially for larger number of geometry parameters. In this work, we propose a novel approach where the region of surrogate model validity is restricted to a manifold spanned by several reference designs corresponding to antenna optimized for various operating frequencies and dielectric permittivity of the substrate material. This allows us to focus the modeling process in the region that only contains designs that are close-to-optimum from the point of view of the aforementioned operating/material criteria. Rigorous analytical formulation of the technique is supported by a case study of a ring slot antenna. Considerable reduction of the number of training points compared to conventional modeling methods is demonstrated.
Statistical Modeling of the Reflection Coefficient of Deformable Antennas
Jinxin Du (Télécom ParisTech & Institut Mines－Télécom, France); Christophe Roblin (Telecom ParisTech & LTCI - Institut Mines-Télécom, France)
A modeling methodology is proposed for characterizing the reflection coefficient S11(f) of narrow band antennas undergoing random disturbances. Firstly, identification techniques are used to get a parsimonious representation of the S11; then the Polynomial Chaos Expansion (PCE) method is used to characterize quantitatively the influence of random disturbances on the compressed S11. The derived S11 model can be used as efficient surrogate for statistical analysis of antennas' frequency behavior. We have applied the proposed methodology to two narrow band antennas - a deformable dipole and a textile patch - in order to demonstrate its performance. Models with good accuracy have been derived for both cases.
A High-Power Wide Beamwidth Circularly Polarized Antenna with Lightning Protection
Bo Wang and William S. W. Cheung (The University of Hong Kong, Hong Kong); Weiyun Wang (Fenghuo Nuoxin Science&Technology Co., P.R. China); Min Li and Ti Yuk (The University of Hong Kong, Hong Kong)
A high-power wide beamwidth circularly polarized (CP) antenna with lightning protection is presented. The antenna is designed to operate at 1.41 GHz with a wide beamwidth for airport uses. It consists of four helix antenna elements forming a quadrifilar-helix antenna (QHA), a strip-line feeding network and a lightning rod for lightning protection. The QHA is fed using a high-power feeding network with sequential phase rotation of 90o. The lightning rod is installed at the center of the ground plane on the base of the antenna. Simulation is used to design and study the antenna which is also fabricated with housing for measurement. Simulation and measured results agree well. Results show that the QHA antenna has a hemispherical radiation pattern with a beamwidth of 100° and a CP beamwidth of 109° in elevation.
A Broadband and Wide Beamwidth Dual Circularly Polarized Antenna Using Crossed Bent Dipoles
Bo Wang and William S. W. Cheung (The University of Hong Kong, Hong Kong); Weiyun Wang (Fenghuo Nuoxin Science&Technology Co., P.R. China); Min Li and Ti Yuk (The University of Hong Kong, Hong Kong)
A broadband and wide-beamwidth dual circularly polarized (CP) antenna is presented in this paper. The antenna consists of two bent dipoles placed in a crossed shape. The dipoles are individually fed with signals with quadrature phases from a 3-dB hybrid coupler chip. A metal cavity serving as a reflector is used to produce a unidirectional radiation pattern. Measurements show that the antenna has an impedance bandwidth of 66.2% (0.98-1.95 GHz) for |S11|<-10 dB, an axial-ratio bandwidth (ARBW) of 51.4% (1.03-1.75 GHz) for AR<3 dB, and a very wide AR beamwidth of over 162° with a maximum AR beamwidth of 260°.
Integrated Rectifying Circuit and Antenna Design with Harmonic Rejection for RF Energy Harvesting
Sharif Ahmed (Universiti Teknikal Malaysia Melaka & UTeM, Malaysia); Zahriladha Zakaria and Mohd Nor Husain (Universiti Teknikal Malaysia Melaka, Malaysia); Ammar Alhegazi (University Technical Malaysia Melaka (UTeM), Malaysia)
This paper presents a rectifying antenna (rectenna) which operates at 2.45 GHz. The antenna consists of two-layer low-cost FR-4 substrates separated by an air gap to enhance the gain. The harmonic rejection property is embedded within the antenna design to eliminate the use of harmonic rejection filter (HRF) between the antenna and rectifier, which reduces the cost and size of the rectenna. The rectifying circuit consists of two stages combined by a power combiner to maximize the output voltage. A fast switching Schottky diode of HSMS 286B is used for rectification process. The measured RF-DC conversion efficiency of the proposed rectenna is 78.7 % at an input power of 20 dBm and load impedance of 4 KΩ. The proposed rectenna can provide high RF-DC conversion efficiency which is suitable for RF energy harvesting applications.
A Technique to Narrow down Radiation Patterns of Broad Beam Antenna Operationally and Its Application to Security Gate to Prevent Shoplifting Based on Monopulse System
Tomoki Sakogawa, Katsuyoshi Aoki and Futoshi Kuroki (National Institute of Technology, Kure College, Japan)
In this paper, a technique to narrow down the radiation patterns of the antenna operationally was proposed while keeping antenna size to be small. The main emphasis was placed on the analog signal processing using the monopulse system having antennas with broad radiation patterns. The sensitivity of arrival angle detection form the RF-tags was newly defined and it was evaluated using the microstrip patch antenna pair with a half power beam width of 150 deg as a function of the antenna pair distance. From the numerical and experimental investigations, it was obvious that the antenna pair distance from fortieth part to tenth part of a free space wavelength guaranteed the narrow beam operation to be less than the range of the arrival angle of 10 deg although the half power beam width of the microstrip path antenna was 150 deg.
Ultra-Wideband Linear Polarization Converters Based on Pixelated Reflecting Metasurfaces
Michele Borgese (Università di Pisa, Italy); Filippo Costa and Simone Genovesi (University of Pisa, Italy); Agostino Monorchio (University of Pisa & CNIT, Italy)
An ultra-wideband linear polarization converting metasurface is presented. The polarizer is based on a periodic arrangement of metallic elements printed on a grounded dielectric substrate. The element geometry of the metasurface is optimized with a genetic algorithm by discretizing the unit cell in a 16x16 pixel matrix. This polarization converter is able to work from 7.03 GHz to 29.01 GHz (121% of bandwidth) with a cross polar reflection coefficient greater than -2 dB. A refinement algorithm is also applied to the optimized cell in order to further extend the operative bandwidth and at the same time remove unnecessary pixels. Finally, the bandwidth is extended up to 129%. The unit cell periodicity is 4.6mm and the thickness of the low loss substrate is 3mm.
A New Circularly Polarized Antenna for GNSS Applications
Umniyyah Ulfa Hussine, Yi Huang and Chaoyun Song (University of Liverpool, United Kingdom (Great Britain))
A new and circularly polarized (CP) antenna is proposed for global navigation satellite systems (GNSS) applications. The antenna employs a single feed and two orthogonally elliptical printed dipoles. The dipoles are crossed through a 90° phase delay line of a vacant-quarter printed ring to achieve CP radiation. In order to achieve broad beamwidth, four metallic cylinders are introduced. The proposed antenna has achieved a bandwidth of about 43% from 1.08 to 1.69 GHz for S11 < -10 dB. Meanwhile, the CP bandwidth is from 1.55 to 1.63 GHz (L1) and 1.12 to 1.26 GHz (L2, L5) for axial ratio < 3 dB. Additionally, the antenna yields right-hand circular polarization (RHCP) and high antenna efficiency over a wide frequency band. The simulated results have shown that the proposed antenna is a good candidate for GNSS applications.
A Compact Wideband 4-Port Circularly Polarized Dielectric Resonator Antenna
Slobodan Jović (Defence R&D Canada, Canada); Michel Clénet (Defence Research and Development Canada, Canada); Yahia Antar (Royal Military College of Canada, Canada)
We present in this paper a novel wideband circularly polarized dielectric resonator antenna (DRA) covering the complete Global Navigation Satellite System (GNSS) frequency band (1150-1620 MHz). This antenna, considering its simplicity, provides excellent performance in terms of gain, axial ratio and beamwidth across the entire operating bandwidth while being relatively low profile and with a design permitting insertion of the RF front-end right below the antenna ground plane. Even though GNSS is the targeted application in this paper, this antenna can be used for other purposes, like in MIMO systems or as a polarization discriminator.
Status Update on the System Validation of APERTIF, the Phased Array Feed System for the Westerbork Synthesis Radio Telescope
Boudewijn Hut (ASTRON Netherlands Institute for Radio Astronomy, The Netherlands); Raymond van den Brink and Wim A. van Cappellen (ASTRON, The Netherlands)
Phased Array Feed (PAF) systems are installed on the Westerbork Dishes, allowing new type of science for the astronomical community. All 12 dishes are equipped with the hardware and the central systems are in place too. The PAFs need a dedicated calibration scheme in order to satisfy stability requirements. The verification process has finished for most system elements, and the first validation test passed with flying colors.
Mechanically Reconfigurable Waveguide-Slot Single Element Using Tuning Screws
Pablo Sanchez-Olivares and Jose Luis Masa-Campos (Universidad Autonoma de Madrid, Spain); Javier Hernandez-Ortega (Universidad Autonoma de Madrid)
A mechanically reconfigurable waveguide-slot single radiating element is presented. The tuning mechanism consists on three metallic screws introduced through the bottom wall of the feeding waveguide. The insertion length of the tuning screws and the distance to the slot are used to control the radiated signal as well as to maintain a good input matching response. Several prototypes with different slot lengths have been manufactured to experimentally validate the reconfigurable performance. The proposed triple tuning screw waveguide-slot radiator provides a low cost and simple mechanism to conform a reconfigurable array antenna
Implementation of 4 x 4 Stacked Patch Array with Corporate Feeding Network for Ku-band Applications
Eduardo Garcia-Marin, Jose Luis Masa-Campos and Pablo Sanchez-Olivares (Universidad Autonoma de Madrid, Spain)
In this work, the experimental implementation of a 4 x 4 stacked-patch array with linear polarization and a corporate feeding network for Ku-band is exposed. The feeding network is split into two levels, with an initial power distribution in Substrate Integrated Waveguide and a second distribution in microstrip technology. The experimental results show a matching coefficient better than -10 dB in a 15.9% bandwidth. In addition, the measured gain attains 16.8 dBi, 0.8 dB below the simulated gain, while radiation efficiency is 66 %. The structure is validated for higher-gain arrays, and hence designs of 8 x 8 and 16 x 16 radiating elements are also proposed and the simulated results presented. Therefore, antennas with several gain values are available in order to suit the different elements of the communication system, such as the end user and the base station.
Broadband Circularly Polarized NFRP Antenna Using Crossed Dipole Driver
Son Xuat Ta (Hanoi University of Science and Technology, Vietnam); Ikmo Park (Ajou University, Korea); Richard W. Ziolkowski (University of Arizona, USA)
This paper presents a planar, broadband, electrically-small, circularly polarized (CP), near field resonant parasitic (NFRP) antenna fed by a crossed dipole driver. The driven and parasitic elements are printed on two separate thin substrates, which are stacked together with no air-gap to achieve the compact planar configuration. The technique of introducing meander lines and arrowhead-shaped endings in both elements is utilized to achieve the electrically small size. The parasitic and driven elements are designed to produce CP radiation at different frequency bands, which are then combined to obtain the broadband characteristic. The final design, whose driven and NFRP elements are implemented on two substrates of the same size, i.e., 35 mm × 35 mm × 0.508 mm, yields a measured |S11| < −10-dB bandwidth of 218 MHz (1.491-1.709 GHz) and 3-dB AR bandwidth of 145 MHz (1.490-1.635 GHz). Additionally, the antenna produces bi-directional radiation and has a high radiation efficiency.
A Highly Miniaturized Loop Excited Quasi-YagiAntenna with High Front-to-Back Ratio
Syed Jehangir (United Arab Emirates University, United Arab Emirates); Mohammad S. Sharawi (King Fahd University of Petroleum and Minerals (KFUPM), Saudi Arabia)
A multi-band Quasi-Yagi antenna based on loop excitation is presented with 68% miniaturization, which is achieved using loop meandering and a novel defected ground structure (DGS), targeting the 2 GHz band. It has a minimum measured -6 dB bandwidth of 249 MHz (0.780-1.029 GHz) in the lower band and 286 MHz (1.932-2.218 GHz) in the upper band covering several LTE bands. The proposed antenna ensures very good Yagi-Uda performance in terms of front-to-back ratio (FBR) and cross-polarization. It has a very high FBR of more than 20 dB with a ground plane width of only 7mm, and has very low cross polarization of -29.3 dB. The gain of the proposed antenna is around 6 dBi, directivity is 8.2 dB, and efficiency is 73%. The size of the miniaturized model is 60 × 50 × 0.8 mm3.
Design of Dual-band Compact Ceramic Chip Antenna for Terminal Applications
Yuan Yao and Haiyang Yu (Beijing University of Posts and Telecommunications, P.R. China); Junsheng Yu (University of Electronic Science and Technology of China, P.R. China); Xiaodong Chen (Queen Mary University of London, United Kingdom (Great Britain))
In this paper, a novel dual band compact antenna based on planar inverted-F antenna (PIFA), ceramic substrate and interdigital coupled structure are proposed. It has compact size with the dimensions of 10.2*3*2.5mm3. The operating mechanisms are illustrated and the study on the key dimension parameters is given. Both the simulation and measurement results are shown to verify the good performance of the antennas. The antenna can operate at both 1.575GHz and 2.45GHz and offers a maximum total gain about 3.21dBi and 3.5dBi respectively. It is suitable for multifunctional applications in terminals.
Cavity-Backed Slot Antenna for Thin Wireless Portable Devices
Rohit Chandra (Sunway Communication AB, Sweden)
A conventional cavity-backed slot antenna (CBSA), excited by a probe, requires a large space due to the size of the resonant cavity especially at lower frequencies. An alternative CBSA antenna can be designed by using a compact non-resonant cavity where the slots are excited. This paper presents such a CBSA for dual-band (2.4 GHz and 5 GHz) Wi-Fi applications for an ultra-thin portable wireless device (like tablet or laptop) with the thickness in the range of 4 mm to 5 mm. The presented antenna is L-shaped and can be placed at the corner of the device. The antenna meets the efficiency requirement that is greater than -7 dB in the 2.4 GHz band and greater than -6 dB in the 5 GHz band. Hence, the presented antenna is a suitable candidate of Bluetooth/Wi-Fi antenna for slim laptops or tablets
Use of a Dielectric Resonator Antenna to Reduce Hand Effect in a Miniature IoT Device
Kaoutar Allabouche (Université SIDI MOHAMED BEN ABDELLAH & Université CÔTE D'AZUR, Morocco); Fabien Ferrero (University Nice Sophia Antipolis, CNRS, LEAT & CREMANT, France); Leonardo Lizzi (Université Côte d'Azur, CNRS, LEAT, France); Jean-Marc Ribero (Université de Nice Sophia Antipolis, France); Mohammed Jorio (FST Fes, Morocco); Najiba El Amrani El Idrissi (faculté des sciences technique de Fés.maroc, Morocco)
In this work, we compare two different antenna topologies integrated in a miniature IoT device working at 900 MHz: Inverted F Antenna (IFA) and Dielectric Resonator Antenna (DRA). This type of handheld device can be strongly impacted by human body effect, consequently we study the radiation performance of the two structures close to a human hand. Electromagnetic simulations show for the IFA a 15 dB decrease of the total efficiency with hand influence, while the DRA total efficiency is only decreased by 2 dB in the same situation.
A Multiband On-Chip Antenna for 94 and 140 GHz Applications
M. Saad Khan and Farooq A. Tahir (National University of Sciences and Technology, Pakistan); Hammad Cheema (School of Elect. Engineering and Comp. Science, National Uni. of Science & Technology, Pakistan)
A bowtie slot on-chip antenna (OCA), exhibiting multiband operation at 94 and 140 GHz is presented. The first of its kind on-chip multiband operation is achieved by adding parasitic loading elements in the slots. The bond-pads along with a shunt-stub, form the impedance matching network of the antenna. Designed in IHP 130nm BiCMOS process, the simulated gain of the proposed antenna is -4.09dBi and -4.76 dBi at 94 GHz and 140 GHz respectively while occupying 494366650 m3. The small on-chip dimensions at mm-wave frequencies along with the presented multiband operation can be extremely useful for supporting multiple upcoming wireless communication applications.
Electromagnetic Feasibility of a Passive Wireless Sensor Network for Temperature Mapping Inside a Shielded Enclosure
Sergio López-Soriano (Universitat Autònoma de Barcelona, Spain); Ivan Spassovsky (ENEA, Italy); Josep Parrón (Universitat Autònoma de Barcelona, Spain); Gaetano Marrocco (University of Rome Tor Vergata, Italy)
This contribution addresses the electromagnetic feasibility of a wireless temperature monitoring inside a portion of a high-power high-frequency Cyclotron Auto-Resonance Maser (CARM) for plasma heating in the new generation of DEMO TOKAMAK machines. The scenario is investigated as potential communication channel for a UHF RFID sensor network where a cavity probe is used to both excite the coaxial cavity and to collect the temperature data scattered back by sensor antennas. Some preliminary designs and prototypes of a simplified model of the cavity and of the reader/sensor devices permit to quantify the feasibility of the architecture and to evaluate the power bounds for stable communication and sensing.
Low Profile RFID Transponder on Conductive and High Permittivity Lossy Dielectric Platforms
Branimir Ivšić (University of Zagreb, Faculty of Electrical Engineering and Computing, Croatia); Anja Kuštra (University of Zagreb, FER, Croatia); Juraj Bartolić (University of Zagreb, Croatia)
The design of folded dipole similar to quarter-wavelength rectangular microstrip patch antenna is shown. A coplanar feeding structure is integrated in the flat radiator and accommodated to accept an RFID microchip to yield efficient operation in body-centric and highly conductive environments. Based on such antenna, an efficient transponder is designed, manufactured and experimentally verified. The transponder showed good isolation between radiating structure and the human body or a conductive platform in 870 MHz band. The reading range of the proposed transceiver is compared with the commercial one.
Coupled Dipole Antennas for on/off-body Communications at 2.45 GHz
Haoran Su and Robert Michael Edwards (Loughborough University, United Kingdom (Great Britain)); Elijah Adegoke (Loughborough University & HSSMI, United Kingdom (Great Britain))
In this paper, three experiments with coupled dipoles were carried out in order to determine the optimal distance where an efficient communication link can be established. The simulations results showed that when the subcutaneous dipole is installed adjacently to the surface of the skin, the dipole mounted above the skin level should be in the range of 20 mm to 25 mm for efficient communication. Subsequently, the influence of the dielectric parameters of the human tissue on wave propagation has also been presented in this work.
Compact Planar Yagi-Uda Antenna with Improved Characteristics
Hemant Kumar and Girish Kumar (IIT Bombay, India)
In this paper, two different designs of 3-element planar Yagi-Uda antenna based on the shape of driven and reflector elements are studied. To feed the driven element of Yagi-Uda antenna, a tapered microstrip balun is designed, which converts unbalanced coaxial feed to balanced microstrip line feed. Measured results of both the antennas are compared and it is shown that a planar Yagi-Uda antenna using tapered shaped dipole elements is more compact and has better characteristics in terms of bandwidth, front to back ratio and gain than that using normal rectangular shaped dipoles. For Yagi-Uda antenna using tapered dipoles, measured bandwidth is 18.6% for return loss less than 10 dB. Maximum gain is 6.4 dBi with less than 1 dB variation over the bandwidth. Measurement shows a peak front to back ratio of 30 dB.
Inkjet-Printed Pixel Antennas with Hexagonal Cells
Bariscan Karaosmanoglu, Sadri Guler, Hande Ibili and Ozgur Ergul (Middle East Technical University, Turkey)
We present a new type of pixel antennas involving hexagonal unit cells that are suitable for fabrication in low- cost inkjet-printing setups. Antennas are optimized in a rigorous simulation environment based on the multilevel fast multipole algorithm integrated into genetic algorithms. Hexagonal cells are suitable for both the optimization environment and fabrication setup. Optimizations are performed particularly to design radio-frequency-identification tags, by removing pixels from a given template to achieve the best performance, e.g., minimum reflection coefficient values and maximum reading ranges. The overall design, optimization, and fabrication procedure has a fast demand response, requiring only one day from a request to the prototype stage.
Design of a Dielectric Waveguide Antenna at Microwave Frequencies
Linghui Kong (KU Leuven, Belgium); Xuezhi Zheng (Katholieke Universiteit Leuven, Belgium); Sen Yan (KU Leuven, Belgium); Guy A. E. Vandenbosch (Katholieke Universiteit Leuven, Belgium)
A dielectric waveguide antenna for X-band is designed. A printed dipole fed by a coplanar strip excites the Ex11 mode inside the dielectric waveguide. The waveguide mode in its turn excites a properly dimensioned patch, which generates the radiation pattern. Simulations are conducted from the stand-alone waveguide up to the complete structure to reveal the coupling and scattering effects between the substrate waveguide and the patch radiator. A pair of prototypes is manufactured and measurements are performed.
Adapted Raised Cosine Window Function for Array Factor Control with Dynamic Range Ratio Limitation
Filipe Santos and Joaquim Azevedo (University of Madeira, Portugal)
The use of window functions to improve the side lobe level of antenna arrays is hindered by high value of excitation currents dynamic range ratio. This paper proposes a fast and iterative window function generation strategy aimed at achieving improved side lobe level starting from a preset current dynamic range ratio. Based on this strategy a new window function is develop for standard set of conditions.
Circular Array Antenna for UAV-UAV Communications
Xiaoliang Sun (Technical University of Madrid, Spain); Rodrigo Blazquez-Garcia (Universidad Politécnica de Madrid, Spain); Alejandro García-Tejero (Technical University of Madrid, Spain); José-Manuel Fernández-González, Mateo Burgos-García and Manuel Sierra-Castañer (Universidad Politécnica de Madrid, Spain)
Nowadays, the communications links limit the autonomy of unmanned aerial vehicles (UAV). In this paper, a multichannel long-range communication link for UAVs with high quality of service, moderate bandwidth and affordable cost is proposed. This link is deployed by using a second UAV as a communications relay and it provides bidirectional coverage for telemetry and telecommand and a high-capacity downlink for video. Our highly compact system can be installed on medium-sized UAVs for air-air links in order to offer greater flight autonomy. This system is based on an active circular array of linearly polarized circular patch antennas which are selectively activated depending on the desired direction of the beam.
Directive Array Based Pattern Reconfigurable Antenna
Kranti Kumar Katare and Animesh Biswas (IIT Kanpur, India); Karu Esselle (Macquarie University, Australia)
In this paper, a high-gain pattern reconfigurable antenna system is presented. It consists of one driven monopole antenna at the centre, which is surrounded by six parasitic elements. Each parasitic element made up of metallic strip, loaded with switch and backed by dielectric layer. Parasitic elements will behave like transparent and opaque surface to a vertically polarized incident wave for OFF and ON states of switch respectively. Therefore entire assembly becomes reconfigurable and beam steering is achieved. Proposed antenna offers a high and uniform gain of ~ 8 dBi with beam steering along the entire azimuth plane. The simulation has been carried out for ISM band (fr=2.45 GHz) using CST Microwave studio software.
Gain Enhancement of Pattern Diversity Antenna by Improving Phase Uniformity
Kranti Kumar Katare and Animesh Biswas (IIT Kanpur, India); Karu Esselle (Macquarie University, Australia)
A pattern diversity antenna, loaded with dielectric phase correcting structure is investigated. Antenna system is fed through monopole, which is surrounded by reconfigurable frequency selective reflector (RFSR). Each RFSR is connected to ground plane via switch. In ON state of switch corresponding RFSR behaves as reflecting surface, whereas it'll become transparent for the OFF state of switch. Thus beam steering can be achieved along the entire azimuth plane by configuring the switching states. Dielectric phase correcting structure (PCS) is incorporated in the direction of beam for transforming non-uniform phase distribution of vertically polarized electric field to nearly uniform phase distribution, which in turn enhances the gain of unloaded antenna by 1.5-2.0 dBi. The simulation has been carried out for ISM band (fr=2.45 GHz) using CST Microwave studio software.
Flexible and Cost Effective Reconfigurable UHF RFID Antenna System
Enrico Tolin (Politecnico di Torino, Italy & IMST GmbH, Germany); Achim Bahr (IMST GmbH, Germany); Matthias Geissler (IMST, Germany); Francesca Vipiana (Politecnico di Torino, Italy)
In this paper a reconfigurable matching network for achieving frequency agility of an electrically small UHF RFID patch antenna is proposed. In order to allow switching under high power transmission a state-of-the-art SP3T CMOS switch is employed for selecting peculiar components and thus achieving a proper matching in the EU and US frequency bands. Moreover, in the proposed design, only one switch is used instead of four needed in standard aperture tuning approaches. An optimized design of a RFID microstrip antenna has been simulated, showing good performance and high grade of flexibility of this technique that, for its low cost and high integration rate, can be an alternative to aperture tuning for frequency agility purpose.
2D Angle of Arrival Estimations and Bandwidth Recognition for Broadband Signals
Noori BniLam (University of Antwerp - iMinds, Belgium); Jan Steckel (University of Antwerp - Cosys-lab Research Group, Belgium); Maarten Weyn (University of Antwerp - imec, Belgium)
In many angle of arrival (AoA) estimation algorithms for broadband signals a-prior knowledge about the impinging signals' bandwidth is required for the algorithms to function. In this paper, we present a new technique for estimating the AoA and the bandwidth of the received broadband signals without requiring any knowledge of the bandwidth of the received signals. The proposed technique consists of a uniform circular array (UCA) followed by a transversal filter. It employs variable bandwidth spatial vectors along with the signal to thermal noise ratio (STNR) estimator to estimate the AoA and the bandwidth of the received signals simultaneously. The simulation results illustrate the capabilities of the proposed technique in estimating not only the elevation and the azimuth of the impinging signals with different bandwidths, but also the bandwidths of these received signals.
Experimental DoA Estimation Performance of the Co-array Concept
Jiachen Wang (KU Leuven, Belgium); Rubén Mena (ETSIT, Departamento de Comunicaciones, Universidad Politécnica de Valencia, Spain); Guy A. E. Vandenbosch (Katholieke Universiteit Leuven, Belgium)
In previous studies, it has been proven that by applying the co-array concept, we can detect the Direction of Arrival (DoA) of more sources with less antenna elements. This paper investigates two parameters that have a crucial influence on the co-arrays' DoA estimation performance in practical tests: near field conditions and a multi-path environment.
3D Compact Antenna Using Liquid Metal and Additive Technologies
Mathieu Cosker (Université côte d'Azur, CNRS, LEAT, France); Leonardo Lizzi (Université Côte d'Azur, CNRS, LEAT, France); Fabien Ferrero (University Nice Sophia Antipolis, CNRS, LEAT & CREMANT, France); Robert Staraj (Universite Cote d'Azur, CNRS, LEAT, France); Jean-Marc Ribero (Université de Nice Sophia Antipolis, France)
This paper presents a miniature antenna in Ultra High Frequency (UHF) band fabricated using liquid metal and additive technologies. Such an approach allows the accurate realization of compact and complex antenna structures. The design as well as the realization of the antenna are discussed. In order to assess the effectiveness of the proposed solution, simulated and measured results are reported. The antenna small dimensions and good efficiency make it a good candidate for internet-of-things (IoT) applications.
Characterization of the Lossyness of Matching Networks for RF Energy-Harvesting Rectennas
Yen-Sheng Chen and Cheng-Wei Chiu (National Taipei University of Technology, Taiwan)
In general, a radio-frequency (RF) energy-harvesting rectenna uses the same structure as that for dedicated RF sources, although the level of input power is completely different. Few studies have investigated whether this situation needs a specific rectenna configuration, and the loss of rectenna elements for low-input-power scenarios has not yet been fully characterized. The purpose of this conference paper is to analyze the lossyness of impedance matching networks for RF energy-harvesting rectennas. The input power studied in this work ranges from -20 dBm to 0 dBm. We evaluate the additional loss of impedance matching networks, showing that the overall efficiency may decrease 95 percent in the worst case. Therefore, we suggest that the rectenna aiming at RF energy harvesting must remove the matching network, provided that the antenna impedance is directly conjugate matched to the input impedance of the rectifier.
Probabilistic VOR Error Due to Several Scatterers - Application to Wind Farms
This paper introduces a method to calculate the VOR error due to multipaths from several known scatterers within known quantiles. In such a configuration, the amplitudes of the multipaths can be numerically or analytically calculated, whereas their phases are modelled as uniformly distributed. A probabilistic formulation of the VOR error that overestimates its variance is introduced to obtain the quantiles. The method is useful to obtain probabilities of occurrence of large VOR errors for multiple configurations and in a short computation time. Examples with wind farms are presented.
Viewpoint Correction for Polarimetric Turntable Inverse Synthetic Aperture Radar
Thomas Dallmann and Dirk Heberling (RWTH Aachen University, Germany)
Turntable ISAR imaging systems generate radar images by rotating the radar target and performing measurements at various angles. The rotation leads to different perspectives onto the scattering centers of the target. This causes problems if polarimetric methods should be applied to the radar image. In this paper this problem is investigated and a correction technique suitable for two-dimensional imaging is proposed. The correction mitigates the effects of a change in perspective. Additionally a criterion is presented which allows to optimize the corrected results in a way which is advantageous for a subsequent polarimetric processing. A comparison of radar images with and without application of the proposed methods shows the validity of the approach.
A Method of Range Measurement Based on High Resolution Range Profile
Xiaoliang Yang (National University of Defense Technology, P.R. China); Fen Ye (Huayin Ordnance test Center of China, P.R. China); Gongjian Wen, Baiyuan Ding and Yi Ge (National University of Defense Technology, P.R. China)
In conventional methods, the weighted mean range of the scattering centers on the high resolution range profile(HRRP) is assumed as the range between the target center and radar. However, this assumption is not reasonable because the scattering center with the maximum amplitude may not locate at the center of the target. In this paper, we proposed a novel range measurement method based on HRRPs. In the proposed method, HRRPs at different target poses are first predicted by the three-dimensional electromagnetic model (3-D em-model) of the target. Then, a slide correlation is conducted to measure the similarity between the HRRP of measurements and the HRRPs predicted by the 3-D em-model. Since the target center is already marked in the 3-D em-model, the position of the target center can be obtained through the correlation. Experimental results using simulated data validate the effectiveness of the proposed method.
A Novel Multi-Tag Identification Technique for Frequency Coded Chipless RFID Systems Based on Look-Up-Table Approach
Ahmed El-Awamry (University of Duisburg-Essen, Germany); Maher Khaliel (Universität Duisburg-Essen, Germany); Abdelfattah Fawky (University of Duisburg Essen, Germany); Thomas Kaiser (Universität Duisburg-Essen, Germany)
The main objective of this contribution is to introduce a novel multi-tag anti-collision protocol based on Look-Up-Table (LUT) scheme. The proposed protocol includes an enhancement for the spectrum utilization and coding capacity. This is accomplished by transferring the tag-ID to be stored in a table in the main memory of the reader (look-up-table). Moreover, the unique signature of each tag represents the address of the tag's ID. The proposed protocol is modeled and simulated for identifying 10-chipless tags in order to set the regulations of the tag and reader design. Moreover, a novel real-world testbed for the multi-tag UWB chipless RFID system based on a software defined radio is introduced. In this testbed, all the signaling schemes related to the transmitted signal, detection techniques, empty room calibration for the clutter removal process and identification protocol are applied.
Frequency Coded Chipless RFID Tag Localization Using Multiple Antennas
Abdelfattah Fawky (University of Duisburg Essen, Germany); Maher Khaliel (Universität Duisburg-Essen, Germany); Ahmed El-Awamry (University of Duisburg-Essen, Germany); Thomas Kaiser (Universität Duisburg-Essen, Germany)
In this paper a frequency coded chipless RFID localization algorithm is proposed. Unlike other techniques, one reader with multiple antennas is used to interrogate, identify and localize the tag. The Received Signal Strength (RSS) technique is used to detect the range of the tag, while Matrix Pencil Method (MPM) is used to calculate the Angle of Arrival (AoA). To validate both techniques a ray tracing tool was used to calculate the system link budget using tag RCS patterns exported from CST-MWS. The ray-tracing tool also calculated the interrogation zone considering all environmental factors. Moreover, a real-time testbed was created using fabricated chipless tags. The testbed was implemented using both measurement tools and Software Defined Radio (SDR). Both simulation and measurements show a great potential for the chipless tag to be used in localization and tracking application.
Indoor Measurements of IoT Wireless Systems Interfered by Impulsive Noise From Fluorescent Lamps
Iratxe Landa, Aitor Blázquez, Manuel Velez and Amaia Arrinda (University of the Basque Country, Spain)
This paper presents the methodology and results of several trials carried out in order to test the effects of impulsive noise source in IoT wireless systems. The impulsive noise generated by fluorescent lamps at 433 MHz and 868 MHz has been measured and recorded. Using these measurements an impulsive noise generator has been developed. Then, with the generated noise two IoT systems have been interfered and the results have been analyzed. The studied systems are a remote control operating at 433.92 MHz and intelligent lighting based on Z-Wave protocol at 868.42 MHz. The methodology of the procedure is explained and the most relevant results are exposed.
Preliminary Results of Medium Wave Mobile Reception Measurements in a Dense Urban Region
Elizabeth Verdugo (PUC/RIO); Luiz da Silva Mello (CETUC-PUC-Rio & Inmetro, Brazil); Marta Pudwell Chaves de Almeida (Inmetro, Brazil)
This paper presents preliminary results of medium wave mobile measurements campaigns carried out in a dense urban region in Brazil. The large-scale and small-scale fading were obtained, as well as probability distribution functions of these signals. The results presented here include daytime and nighttime statistics of the mobility measurements results.
Classification of GNSS SNR Data for Different Environments and Satellite Orbital Information
In this paper, a data classification method for analyzing the aspects of Signal-to-Noise Ratio (SNR) for Global Navigation Satellite System (GNSS) in real conditions is introduced. Different parts of measured environments and the orbital information of satellites are used as criteria for data classification. It consists of: 1) taking fish eye images of measured routes; 2) dividing measured environments into four potential sub environments (open area, forest area, single building blockage, and street canyon); 3) classifying satellites into nine different groups as function of elevation angles; and 4) creating a table containing the information of mean and standard deviation of SNR for different environments and satellite elevation angles. Results show good correlation of SNR's between same sub environments for different satellite elevation ranges which offer useful insight to regenerate a generalized set of SNR parameters in the laboratory environment for the development of 3D GNSS channel model.
Water Vapor Density Profile Statistics in the Atmospheric Boundary Layer
Pavel Valtr (Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic); Pavel Pechac (Czech Technical University in Prague, Czech Republic); Martin Grabner (Czech Metrology Institute, Czech Republic)
One year statistics of water vapor density is presented. Measured data presented were obtained using meteorological sensors mounted on a mast, thus having very good height and temporal resolution. Measurement results are in the form of surface water vapor density and water vapor density gradient. Results of measurement data analysis are compared with values recommended by ITU-R.
An Assessment of Different Optimization Strategies for Location Tracking with an Android Application on a Smartphone
David Plets (Ghent University - imec, Belgium); Alexander Sels (UGent, Belgium); Jens Trogh (Ghent University, Belgium); Kris Vanhecke (Ghent University - imec, Belgium); Luc Martens (Ghent University, Belgium); Wout Joseph (Ghent University/IMEC, Belgium)
This paper presents a study of the efficacy of different optimization strategies for location tracking on an Android App that is run on a smartphone. The basic algorithm determines the most probable path of the user within a WiFi network by comparing raw RSSI measurements at each location with values in a fingerprint database. The investigated optimization strategies include: accounting for previous locations, increasing the number of WiFi scans per location, applying a Kalman filter, exploiting accelerometer data, shifting the frequency band from 2.4 to 5 GHz, and changing the position of the smartphone with respect to the body. It is shown that especially the accelerometer data allow enhancing the location estimation significantly. By combining different techniques, an average accuracy better than 2 m can be achieved.

#### Poster_04

Wireless Networks / Regular Session / Antennas
Room: Poster Sessions: Corridor Paris
Chairs: Juha Ala-Laurinaho (Aalto University, Finland), Philippe Ratajczak (Orange Labs, France)
Compact Dual-band WLAN(2.45/5.5 GHz) Antenna for USB Dongle Application with Reduced EMI Toward Laptop Circuit Board
Yunnan Jin and Jaehoon Choi (Hanyang University, Korea)
A compact dual-band antenna for WLAN (2.45/5.5 GHz) application is proposed. The proposed antenna consists of two inverted L-shaped radiating elements, a slotted ground plane, a U-shaped shorted metal rim, and a loop feeding structure. The antenna satisfies the -6 dB reflection coefficient bandwidth requirement in WLAN (2.45/5.5 GHz) bands. To apply the proposed antenna to a practical laptop, an equivalent laptop circuit board is considered in this work. This antenna attains a multiband, size miniaturization, and EMI reduction toward a laptop main board. In addition, this antenna reduces the electric field radiated toward the main electric device after plugging into a dongle.
Omnidirectional Dual-Reflector Antennas for High Directivity over Wideband in Millimeter Waves
Rafael A. Penchel (São Paulo State University (UNESP), Brazil); Sandro R. Zang and Jose R Bergmann (PUC-Rio, Brazil); Fernando Moreira (Federal University of Minas Gerais, Brazil)
This work presents a study of the electromagnetic performance of classical and shaped omnidirectional dual-reflector antennas in millimeter waves. An algorithms based on the concatenation of conic sections has been used to synthesize sub- and main-reflectors in order to provide a uniform phase and amplitude aperture distributions. The frequency analysis is focused on antenna radiation patterns across a 20% bandwidth, in order to establish band limits for omnidirectional dual-reflector antennas. The rigorous electromagnetic analysis was accomplished by a hybrid technique based on Mode Matching and Method of Moments.
On Error Rate Performance of a MIMO WLAN System in the Indoor Hotspot Scenario
Xiaoming Chen (Xi'an Jiaotong University, P.R. China); Qi Wu and Shuang Guo (Beihang University, P.R. China)
In this paper, the error rate performance of a multiple-input multiple-output (MIMO) wireless local area network (WLAN) system is evaluated in the indoor hotspot scenario. A realistic three-port MIMO antenna is used at the access point (AP), whereas dipole antennas are assumed at the user terminal. The effects of the channel delay spread and oscillator phase noise on the MIMO WLAN system are studied with respect to the IEEE 802.11n protocol.
A Compact Four-element MIMO Antenna Based on HMSIW Slot Antenna
Wei Ming (Xi'an Research Institute of Navigation Technology, P.R. China); Liu Hu (Xidian University, P.R. China); Wan Tao (Xi’an Research Institute of Navigation Technology, P.R. China); Ying Liu (Xidian University, P.R. China)
A novel four-element MIMO antenna operating at millimeter wave band is proposed. The half-mode substrate waveguide(HMSIW) cavity slot antenna is used as the element to realize a compact structure, high radiation efficiency and interelement isolation. The simulated relative impedance bandwidth is 29.6% from 23.5-31.0GHz for S11<-10dB. And the isolation is lower than -22dB across the operating band without any additional coupling reduction structure.
60 GHz Low Cross Polarized E-Plane AFTSA-SC Array Architecture
Zouhair Briqech (Institut National de la Recherche Scientifique - INRS, Canada); Shraman Gupta and Abdel R. Sebak (Concordia University, Canada); Tayeb A. Denidni (INRS-EMT, Canada)
A four element low cross polarization sine corrugated antipodal Fermi tapered slot antenna (AFTSA-SC) based on E-plane array architecture is designed to operate at 60 GHz and to cover the ISM band. The single element antenna is capable of achieving wide bandwidth (55-65 GHz) with a stable gain (~15 dB) and 88 % total radiation efficiency. A 1 × 4 AFTSA-SC array with E-plane array architecture is analyzed comparing conventional and mirrored array structures. These two array structures have better, and improved antenna gain (~ 20 dB), low sidelobe level (SLL), and reduced cross-polarization while maintaining the antenna's stable radiation characteristics. The proposed mirrored array architecture improved the cross polarization level by 16 dB as a result of which the E-plane AFTSA-SC array architecture is capable of achieving a high gain at E-plane with a narrow beamwidth, lower SLL and improved X-Pol than with the H-plane.
Low Cross Polarized AFTSA-SC H-Plane Array Architecture for MMW Applications
Zouhair Briqech (Institut National de la Recherche Scientifique - INRS, Canada); Shraman Gupta and Abdel R. Sebak (Concordia University, Canada); Tayeb A. Denidni (INRS-EMT, Canada)
This paper presents a high gain, and low cross polarized four element sine shaped antipodal Fermi tapered slot antenna (AFTSA-SC) based on H-plane array architecture that operates at 57-64 GHz for applications in millimeter wave systems. The proposed antenna consists of circular slots and sine-shaped corrugation to enhance the radiation characteristics of the antenna. This antenna is analyzed in H-plane array architecture comparing conventional and mirrored array structures. The performance of the 1 × 4 AFTSA-SC array is investigated not only for lower cross-polarization, but also regarding achieving high gain, better radiation characteristics, and low side lobe level. The proposed mirrored H-Plane array structure exhibits a gain of 20 in addition to good cross-polarization, which is less than −40 dB in both the E- and H-planes at 60 GHz.
Design, Fabrication and Characterization of a New Wideband Antenna Based on a Polyaniline/Carbon Coated Cobalt Composite
Zahir Hamouda (Institut Aéronautique, Université de Blida, Algeria); Jean-Luc Wojkiewicz (Université Lille Nord de France, France); A Pud (Institut of Bioorganic Chemistry and Petrochemistry of NASU, Ukraine); Lamine Kone (University of Lille, France); S Bergheul (Laboratoire des Sciences Aéronautiques, Université de Blida, Algeria); Tuami Lasri (IEMN - University of Lille, France)
The new generation of polymer materials has the facility to conduct electricity, radiate and concurrently be flexible. Accordingly, the possibility of implementation of a flexible antenna opens the door to many interesting applications including body-worn ones. This paper presents the design of a CPW-fed monopole antenna, based on a Carbon coated Cobalt (CCo) charged Polyaniline (PANI). A wideband antenna design approach is proposed to develop a single antenna that can be employed by diverse wireless technologies. In particular, in this paper the frequency bands of interest are [2.4 - 2.48] GHz (WiFi) and [5.15-5.825] GHz (wireless networks). Conception, realization and characterization steps of the composite based wideband antenna are presented. The composite (PANI/CCo) fabricated, whose morphology was studied via scanning electron microscopy, has a conductivity of 7500 S/m. The antenna is printed on a 130μm thick Kapton® substrate. A good agreement between measurements and simulation data is observed.
Electrically Small Structural Antenna Design for Small UAV Based on Characteristics Modes
Sek-Meng Sow (National University of Singapore & Temasek Laboratories, Singapore); Lu Guo (National University of Singapore, Singapore); Shi-Gang Zhou (Temasek Laboratories, National University of Singapore, Singapore); Tan-Huat Chio (National University of Singapore, Singapore)
A systematic approach in developing a 4-port structural antenna on a Small Unmanned Aerial Vehicle is presented. The largest dimension of the SUAV is 0.67 wavelength of the operating frequency. Using Characteristic Mode (CM) Analysis, two CMs with good radiation efficiency are identified. The radiation patterns of these CMs can be synthesized by combining the individual element gain patterns with specific amplitude and phase settings. In addition, the radiation pattern may be gradually steered from one CM to another by progressively changing the phase settings. A 1:5 scaled model is fabricated and the respective CMs are excited; the gain patterns are measured in an anechoic chamber. The resulting gain patterns can be combined either via a suitable RF combiner or digitally beamformed. In both cases, the results agree well. This method may be used to provide steering, albeit limited, of the gain pattern of an electrically small structural antenna.
Investigation of Multi-Beam Multi-Port MIMO Antennas for WLAN/WiMAX Applications
Yan Pan, Yuehui Cui and RongLin Li (South China University of Technology, P.R. China)
Dual-polarized triple-band multi-beam multiple input multiple output (MIMO) antennas are developed for WLAN/WiMAX access points. A four-beam MIMO antenna and a thirty-two-port four-beam MIMO antenna are investigated for high-capacity and wide-coverage wireless applications in high-density environment.
Analysis and Design of a Broadband Dual-Polarized Planar Antenna for 2G/3G/4G Base Stations
Yuehui Cui and RongLin Li (South China University of Technology, P.R. China)
A broadband dual-polarized dual-dipole (DPDD) planar antenna is analyzed and designed for 2G/3G/4G base stations. The DPDD antenna consists of two perpendicularly crossed dual-dipole elements. Each dual-dipole element is comprised of two identical side-by-side dipoles which are connected through a coplanar strip line that also acts as an impedance transformer. Two dual-dipole elements are printed respectively on two sides of a thin substrate and are excited directly by two coaxial cables, making the antenna configuration planar, compact, and simple.
Compact Penta Band Printed Slot Antenna for GSM, Bluetooth, WiMAX, 4G LTE, and WLAN Applications
Mohammad Mehdi Samadi Taheri and Abdolali Abdipour (Amirkabir University of Technology, Iran); Gert Pedersen (Aalborg University, Denmark)
In this paper a compact penta band printed slot Antenna suitable for GSM/Bluetooth/LTE/WiMAX/4G/WLAN application is presented. The antenna is flower shape printed slot antenna which operates in wide band frequency range. By inserting elliptic shape protrudent stubs in the ground plane, some rejection bands in the pass band are attained. The antenna covers GSM and 4G (LTE) bands at center frequencies of 1.8 GHz, Bluetooth at 2.4 GHz, WiMAX at 2.5, 3.5, and 5.8 GHz, WLAN at 2.4, 5.2, and 5.8GHz. the antenna has a good omnidirectional radiation pattern and good matching (S11< -10 dB) all over the passed frequency bands.
A Wideband Endfire CP Antenna Using Magnetic Dipole
Min Li, William S. W. Cheung, Bo Wang and Ti Yuk (The University of Hong Kong, Hong Kong)
This paper presents a wideband circularly polarized (CP) antenna with high gain and end-fire radiation. The antenna consists of two metal strips on the same side of two substrates separated at a distance of 0.09 wavelength. The two metal strips are shorted together at three edges. Two pairs of tapered stubs are protruded from the metal strips to generate two resonances and two orthogonal electric fields with 90o-phase difference, resulting in a wideband CP antenna. Simulation results show that the antenna has a wide impedance bandwidth (IMBW) of 2.31-4.00 GHz (53.6%) for S11<-10 dB and axial-ratio bandwidth (ARBW) of 2.30-3.81 GHz (49.4%) for AR<3 dB. Stable endfire radiation is observed over the operating bandwidth with a peak gain of 7.83 dBi. The antenna is a good candidate for uses in radio frequency identification (RFID) readers to cover the ISM band.
Two-Port Compact Wideband Planar MIMO Antenna
Mirmehdi Seyyedesfahlan (Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland); Ibrahim Tekin (Sabanci University, Turkey)
A wideband dual feed antenna is designed and manufactured for multi-input, multi-output (MIMO) application. The antenna is optimized to match the ports to 50 ohm, and adjust the isolation between the ports for more than 15 dB in 2-6 GHz frequency band. The disk is fed using the microstrip transmission lines with 90° angular spacing to reduce the cross polarization and hence coupling between the ports. Due to the disk radiator, the antenna can be utilized as a two ports omnidirectional antenna. The antenna is measured for S-parameters and gain that comply well with the simulations. Antenna measured gain varies between 2.3 dBi and 6.3 dBi for 2-6 GHz. The antenna can be employed as a two port compact antenna, for multiband communication in 2-6 GHz and for WLAN applications.
Split Ring Resonator with Rotated Inner Ring for Microstrip Circular UWB Antenna
Mousa Hussein, Elham Serria, Ali Hakam and Indu Rajmohan (UAE University, United Arab Emirates)
3x3 Split Ring resonators with inner ring rotation are etched at the back side of Circular microstrip antenna with elliptical rings. Rotation for multiple angles leads to an enhancement in impedance bandwidth. The selected UWB antenna has fabrication dimensions of 45 mm×31 mm×1.27 mm. The rotation of the inner rings occur clockwise and counter clockwise for -47°, 33° and 10°. The preferable enhanced frequency bandwidth is between 2.2 GHz and 9 GHz with return loss up to -28dB at 3.8 GHz. S11, VSWR, maximum gain and group delay are obtained for the new design of the antenna via HFSS. This method of rotating inner or outer rings of SRRs will have massive researches in the near future.
Low-Cost Wideband Antenna on Paper Substrate
Hong Phuong Phan (IMEP-LAHC, Grenoble INP & Ho Chi Minh city University of Technology, France); Tan Phu Vuong (Grenoble INP-MINATEC, France); Philippe Benech (Université de Grenoble-Alpes, Laboratoire IMEP–LAHC, France); Pascal Xavier (UJF Grenoble, France); Pascal Borel and Anastasia Delattre (CTP Grenoble, France)
In this paper, a wide-band monopole antenna structure printed on 104-um E4D paper, a thin, flexible and low cost substrate, has been proposed. For the design process, E4D paper was characterized to obtain its electromagnetic properties by the cavity perturbation method with a cylindrical cavity. Then the antenna was designed and optimized to a wide range of frequency, from 2 GHz to 10 GHz focusing on two WLAN bands. Our proposed antenna is thin, flexible, rather compact, has good performance with the return loss of over 20 dB at 2.45 GHz, over 30 dB at 5.5 GHz. It exhibits very large bandwidth (2.15 GHz to over 10 GHz). The radiation patterns are nearly omni-directional at 2.45 GHz and more directive at 5.5 GHz. The design was realized by screen printing technology at CTP. The measurement results are in good agreement with the simulation which confirms the validity of the design.
A Wide-band Circularly Polarized Slot Antenna by Using Novel Feeding Structure
Mohammad Saeid Ghaffarian and Gholamreza Moradi (Amirkabir University of Technology, Iran); Pedram Mousavi (University of Alberta, Canada)
A novel single-feed wide band planar circularly polarized (CP) slot antenna is presented. This slot antenna consists of an L-shaped feeding stub with metamaterial inspired complementary split ring resonator (MICSRR) and a wide 45º rotated square aperture. Broadband impedance and CP radiation bandwidth (BW) is achieved by using a novel artificial exciting stub with defecting CSRRs on it. By controlling the excitation phase of L-shaped stub, a desirable circular polarization can be generated and both impedance and CP BWs are considerably increased by up to 89%. The operating frequency ranges in S/C band from 2.4-6.22 GHz. The measured bandwidths of 3-dB axial ratio (AR) and VSWR<2 are around 91% (2.4-6.4 GHz) and 89% (2.4-6.22 GHz), respectively.
Compact Wideband Circularly Polarized Slotted Ground Plane Antenna for Mobile Terminals
Oluyemi Peter Falade (Queen Mary University of London, United Kingdom (Great Britain)); Xiaodong Chen (Queen Mary, University of London, United Kingdom (Great Britain)); Clive Parini (QMUL, United Kingdom (Great Britain))
A low cost, simple and compact wideband circularly polarized slotted ground plane antenna design is proposed for mobile terminal. The dual annular perturbation slots antenna with asymmetric stub is built on the grounded substrate. The antenna is design to operate in a wideband that covers 1.85-3.02 GHz frequency band at 10 dB. The circularly polarized radiation patterns have been achieved through the perturbation of the ring slots and the optimization of the asymmetric stubs and the slotted ground plane. The antenna is fed by a single microstrip line place beneath the substrate. A prototype of the proposed antenna has been fabricated and experimentally validated in an anechoic chamber.
An X-type CRLH Leaky Wave Antenna with Low Cross-Polarization
Yu-Wei Wang and Yao-Wen Hsu (Graduate Institute of Communication Engineering, National Taiwan University, Taiwan); Yi-Cheng Lin (National Taiwan University, Taiwan)
we designed a leaky wave antenna based on X-type composite right/left handed (CRLH) transmission line. Due to the wide-band nature of X-type CRLH transmission line, the antenna can provide a wide impedance bandwidth. The antenna can provide 5dB scanning pattern from 5.6GHz to 7.6GHz. The presented antenna shows a significantly low level of cross-polarized patterns using the balanced symmetric.
Characteristic Modes Optimisation Approach to Design a Wideband Electrically Small Antenna
Hussein Jaafar (Universté de Rennes1 & IETR, France); Sylvain Collardey (University of Rennes 1, France); Dominique Lemur (IETR, Universite' de Rennes 1, France); Abdullah Haskou (IETR UMR CNRS 6164, Université de Rennes1, France); Ala Sharaiha (Université de Rennes 1 & IETR, France)
A design methodology based on the combination of the Theory of Characteristic Modes (TCM) with an Optimization Algorithm, to design a wideband Electrically Small Antenna (ESA) is presented. Unlike other design techniques, loads or matching networks are not needed at the input of the antenna. A design example of an Inverted-L Antenna (ILA) is presented to validate the effectiveness of this technique.
SAR Impact Evaluation on Jeans Wearable Antennas
Ignacio Gil (Universitat Politècnica de Catalunya, Spain); Raul Fernandez-Garcia (Universitat Politecnica de Catalunya, Spain)
This paper addresses the effects of two main microstrip wearable antennas on the specific absorption rate (SAR) on the human trunk as well as their impact performance in terms of gain, efficiency and required area. Rectangular patch and PIFA jeans wearable antennas intended for wireless body area network applications at 2.45 GHz are under analysis. The SAR values averaged over 1 g and 10 g tissue of a realistic voxel model are computed according to the IEEE/IEC 62704-1 standard. The results are compared with the limits of exposure determined by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the IEEE C95.1.
Dual-Band WLAN Button Antenna for Both on and off-Body Applications
Xiaomu Hu, Sen Yan and Jiahao Zhang (KU Leuven, Belgium); Guy A. E. Vandenbosch (Katholieke Universiteit Leuven, Belgium)
A novel button antenna for WLAN applications is proposed. The antenna is composed of a button on top of a dielectric disc. The button is located on top of a textile substrate and a conductive textile ground. This antenna shows two different types of radiation patterns, a monopole type pattern in the 2.4 GHz band and a broadside type pattern in the 5 GHz band, thus both on and off-body function can be achieved. Measurements agree very well with simulations.
Design of a Pattern Reconfigurable Antenna with Single Patch Base on Butler Matrix Feeding Network
Wang Yi and Tao Wan (Xi'an Reserch Institute of Navigation Technology, P.R. China); Bochao Yang (Xi'an Research Institute of Navigation Technology, P.R. China)
A novel pattern reconfigurable antenna with single microstrip patch which excited by a butler matrix network for wireless communications is presented. Four steerable beams including boresight, conical and two slant patterns are obtained by changing the current distribution on the patch. The dimensions of the proposed antenna are 100×100×3 mm3 and it is fabricated and tested. Base on the -10 dB return loss, the operating bands can be employed between 2.3-2.5 GHz, which 8% bandwidth for center frequency.
Highly Broadband Circular Polarized Patch Antenna with 3 Phase Feed Structure
Robin Theunis and Maarten Baert (KU Leuven, Belgium); Paul Leroux (Katholieke Hogeschool Kempen, Belgium); Wim Dehaene (Katholieke Universiteit Leuven, Belgium)
In this paper a highly broadband circularly polarized patch antenna design is shown. The design features several novelties which includes the use of a 3-phase feed circular patch for optimal axial ratio and the 3-phase microstrip feed structure to excite the patch antenna. Combining those techniques provides superior bandwidth in both return loss and axial ratio compared to classical rectangular patch designs as shown by simulation and measurements.
Reducing the Width of Planar Yagi-Uda Antennas Using Square-Shaped Split Ring Resonators (SRRs)
Pau Aguilà (Universitat Autònoma de Barcelona, Spain); Gerard Zamora (Universitat Autonoma de Barcelona, Spain); Simone Zuffanelli (Universitat Autònoma de Barcelona, Spain); Ferran Paredes (Universitat Autonoma de Barcelona, Spain); Ferran Martín (Universidad autónoma de Barcelona, Spain); Jordi Bonache (Universidad Autónoma de Barcelona, Spain)
A novel planar Yagi-Uda antenna is proposed in this work. The canonical dipole resonators constituting the driven, reflector and director elements are replaced here with square-shaped split-ring resonators (SRRs). This solution allows for a reduction of the width of the antenna roughly by a factor of two, while maintaining good radiation performance. As a proof of concept, a 5-elements prototype working within the WLAN frequency band is designed and fabricated. The measurements exhibit reasonably good agreement with simulations, and highlight the validity of the proposed approach for obtaining compact Yagi-Uda arrays in planar geometry.
A 2x2 Integrated Filter Antenna Array
Anuj Kumar Sahoo (PDPM IIITDM Jabalpur, India); Ravi Dutt Gupta (PDPM-Indian Institute of Information Technology, Design and Manufacturing, India); Manoj Singh Parihar (IIITDM, India)
This paper deals with a 2x2 Integrated Filter Antenna (IFA) array designed at 5.2 GHz. By incorporating the filtering action in the conventional antenna array the need for an additional filter following the antenna array, for suppressing the out-of-band signals, has been avoided. To achieve this, the last resonator of the filter has been replaced by a slot antenna operating at the same band as that of the filter in each arm of the array. The overall dimension of the subsystem has been optimized to 1.56λ0 x 1.56λ0. It has got a fractional bandwidth of 3.0% at 5.2 GHz. The sub-system provides a maximum gain of 12.43 dBi and HPBW of 33 degrees in broadside direction. The proposed structure was designed, simulated and fabricated. The measured reflection co-efficient plot shows a shift of 0.09 GHz of the overall band which may be due to the fabrication tolerances.
Suppression of Mutual Coupling in Wideband Tree Shaped Fractal DRA Array for MIMO Applications
Kedar Trivedi (Institute of Technology, Nirma University, India); Dhaval Pujara (Nirma University, India)
A closely spaced two-element wideband tree shaped fractal dielectric resonator antenna (DRA) design with low mutual coupling over a wide band of 4.05-10 GHz is proposed. By properly arranging array elements, and using C-shaped periodic defected ground structure (PDGS), mutual coupling reduction has been achieved. Mutual coupling less than -15dB over the entire band of interest is achieved. Conformal strip feeding of trapezoidal shape is used to achieve wide bandwidth of about 84.7%. Different design parameters, radiation patterns with and without PDGS and its associated results are discussed in this paper.
Green 4g Radio Network Planning
Energy-efficient planning is a challenge for heterogeneous 4g wireless networks, since 'greener' strategies typically act against the growing traffic requirements. However, network- wide optimization of base-station antenna patterns can be exploited to that end, leading the total transmit power of the network to a global minimum. This article formulates the coverage and capacity optimization problem in the context of 4g systems and uses a multi-objective genetic algorithm in order to optimize each sector transmitted power, as well as antenna pattern with respect to its pointing direction and 3dB beamwidth. The proposed optimization algorithm is applied to provide the most power efficient network setup that, can be also optimized to leave the least possible coverage holes in the network area in exchange of further power reduction. The trade-off between transmitted power and coverage can be observed leaving further choices to the network designer.
Frequency Reconfigurable Patch Antenna with Defected Ground Structure Using Varactor Diodes
Zakaria Mahlaoui (Cadi Ayyad University & Universitat Politècnica de València, Spain); Eva Antonino-Daviu and Miguel Ferrando-Bataller (Universitat Politècnica de València, Spain); Hamza Benchakroun (iTeam, Universitat Poltècnica de València & Information Technology and Modeling Laboratory, National School of Applied Sciences, Cadi Ayyad University, Spain); Adnane Latif (Cadi Ayyad University, Morocco)
This paper presents an approach that combines two methods for reducing the size of a patch antenna and obtaining a wide tunability frequency range. The addition of a slot in the ground plan helps to shift down the basic frequency of the patch from 7.273 GHz to 4.267 GHz without modifying the basic geometry of the antenna. By modifying the varactor values, a series of successive bands are obtained, ranging from 4.65 GHz to 6.18 GHz. Accurate simulations are performed by using S-Parameter varactor data files. The patch antenna is suitable for U-NII band applications.
Unidirectional Frequency Reconfigurable Bow-Tie Antenna Array with AMC Reflector
Qi Li (China Academy of Space Technology ( Xi'an), P.R. China); Tong Li (Air Force Engineering University of CPLA, P.R. China); Zhipeng Li and Jinyong Fang (China Academy of Space Technology ( Xi'an), P.R. China)
A unidirectional frequency reconfigurable bow-tie antenna array (FRBAA) is presented. The array employs four doubled-sided bow-tie antennas as the radiating elements. By controlling the states of the PIN diodes mounted on the radiators, three switchable operating bands can be achieved. In order to produce unidirectional radiation patterns with low profile and good impedance matching in all the bands, a tri-band artificial magnetic conductor (AMC) is designed and incorporated with the array. The distance between the array layer to the AMC reflector is only 0.032λ0 at the lowest operating frequency (2.4 GHz). The integration of the AMC not only yields good front-to-back ratios, but also improves the forward gains in all the operating bands.
Systematic Design of 3-port Bug-like MIMO Antenna Based on Theory of Characteristic Mode
Dong-Woo Kim and Sangwook Nam (Seoul National University, Korea)
In this paper, 3-port bug-like MIMO antenna design based on theory of characteristic mode is proposed. The proposed antenna has compact size of 30×70× 10 ??? and it operates at 2.4-GHz ISM band. We present novel design approach for 3-port MIMO antenna. First, as it is bilateral symmetric structure, it is possible to decompose characteristic currents with even/odd currents with respect to axis of symmetry. Second, we define characteristic current correlation for finding optimal position of excitation for 3-port MIMO antenna. Finally, we design systematic design of antenna and decoupling and feeding networks by using antenna as a ground plane. Results show that the proposed 3-port MIMO antenna is appropriate to MIMO communication systems in bilateral symmetric structure.
Broadband Collocated Antennas with Three Orthogonal Polarizations
Halim Boutayeb (Antenna Department, Huawei Technologies Canada Co., Ltd., Kanata, Canada); Paul Watson (Huawei Technologies, Canada)
In this work, new designs of three collocated antennas, with orthogonal polarizations, are presented. These types of antennas can find applications in Multiple Inputs Multiple Outputs (MIMO) systems or in base stations antenna arrays. A cross-dipoles and a folded monopole are designed and optimized. Two configurations are analyzed at 2.45GHz and 5.5GHz with broadband and high isolation performance characteristics. The monopole is tested with two or four arms, and the dipole height is either a quarter-wavelength or half-wavelength for broadside or conical radiations. Numerical and experimental results are presented to validate the proposed concept.
A Novel Band Pass Filter Using Radial Stub for GSM Applications with Stopband for GPS
Hossein Omidi (Iran University of Science and Technology, Iran); Morteza Nadi (Iran University of Science & Technology, Iran); Homayoon Oraizi (Iran University of Science and Technology, Iran)
This paper presents a novel approach for designing bandpass filter to global system for mobile communication and stop band for global positioning system. Its configuration consists of is composed of coupled radial stubs and two short circuited stubs on the input and output lines. It has a sharp roll-off and provides a narrowband bandpass filter with 3dB fractional bandwidth of 8.1% in global system for mobile communication band and an insertion loss of 0.5 dB. The transmission zero is located on the global positioning system band. The measured results exhibit good agreement with the simulations.
Design of A Dual-Notched Ultra-Wideband (UWB) Planar Antenna Using L-Shaped Bandstop Resonator
Sam Weng Yik (UTEM, Malaysia); Zahriladha Zakaria (Universiti Teknikal Malaysia Melaka, Malaysia)
In this paper, a novel UWB printed circuit board antenna with dual band-notched characteristics is presented. The antenna consists of a circular patch with two pairs of the L-resonator. To realize the notch characteristics in WLAN at 5.2 GHz (5.15-5.35 GHz) and 5.8 GHz (5.725-5.875 GHz) bands, the half wavelength of L-resonator is introduced in the radiating patch. The T-shape notch is etched in the ground plane to enhance the bandwidth which covers the resonant frequency range from 3.048-10.561 GHz. The effects of L-resonator on the band-notched characteristics are also investigated. The proposed antenna with band-notches shows good impedance matching for the simulated in the physical layout. Furthermore, the proposed antenna has a compact size of 29 x 40 mm2. This proposed design can provides an alternative solution for the UWB wireless system in the designing of a band-notched antenna with a very good notch band.
Preliminary Investigation of Power Delay Profile Computation from Full Wave Frequency Domain Indoor Propagation Model
Ian Kavanagh and Conor Brennan (Dublin City University, Ireland)
New developments in energy efficient wireless communications systems and indoor location and tracking algorithms have created a greater demand for accurate propagation models. In this paper a frequency domain full wave propagation model is used to produce accurate power delay profile information. The propagation model is based on the volume electric field integral equation (VEFIE). The VEFIE is solved in two dimensions at a number of frequencies and the fourier transform is applied to convert the frequency domain data to the time domain. The generated PDP is compared against the well known theory of geometrical optics and a very good agreement is achieved. The effects of finite bandwidth and resolution on the PDPs are also investigated.
Efficient Feedback Quantization for WLAN
Moussa Diallo, Diop Idy and Dioum Ibra (UCAD, Senegal)
We present an efficient feedback quantization technic for beamforming matrix compression. The proposed technic named time domain quantization TD-Q relies on the feed back of time domain parameters necessary for the reproduction of the beamforming matrix at the transmitter. This TD-Q presents the same performance than the conventional Givens rotation quantization GR-Q and requires less amount of feedback. The quantization error, BER performance and amount of feedback of the proposed TD-Q are studied and compared with the GR-Q in IEEE 802.11ac context.
Antenna Design for Underwater Wireless Telemetry Systems
Thierry Deschamps de Paillette (Université de La Rochelle, France); Alain Gaugue (La Rochelle University, France); Emmanuel Parlier and Sylvain Dardenne (Flex-Sense, France)
Underwater environmental sensor networks require wireless communications that can be performed using electromagnetic waves. Water induces both conduction and dielectric losses. Thus, antenna design is a key factor regarding the global performance of such underwater transmission systems. In this article, the study of the seawater properties leads to comparing the conduction and dielectric propagation modes of an electromagnetic wave. A simulation model of an original antenna design is proposed to optimize link budget in underwater communication systems.
A Novel Implantable Printed Dipole with Improved Gain
Motti Haridim (Holon Institute of Technology, Israel); Or Keren and Adi Amitt (Holon Institute of Technology); Mehdi Azadmehr (University College of Southeast Norway)
This paper presents a novel planar implantable dipole antenna operating at the Medical Device Radio Communications Services band (401-406 MHz). The proposed antenna's physical volume is 19.8 mm3. The antenna exhibits gain and efficiency improvement over similar implantable dipoles through combining a square spiral with a short plain strip in each dipole arm. The antenna's gain is -24.6 dB, and its efficiency is 0.09%. SAR simulation results are also presented.

#### Poster_05

Space / Regular Session / Antennas
Room: Poster Sessions: Corridor Top
Chairs: Ana Arboleya (University of Nice-Sophia Antipolis, France), Pawel Kabacik (Wroclaw University of Science and Technology, Poland)
The SKA Low-Frequency Telescope: Performance Parameters and Constraints on the Array Configuration
Maria Grazia Labate, Peter Dewdney, Robert Braun, Mark Waterson and Jeff Wagg (SKA Organisation, United Kingdom (Great Britain))
The SKA1-LOW radio telescope will be a low-frequency (50-350 MHz) aperture array composed by ~130,000 antenna elements spread over tens of kilometers and located in Western Australia. Its scientific objectives will prioritize studies of the Epoch of Reionization and pulsar physics. This paper will focus on the key performance parameters and constraints driving the architectural design of the World's largest antenna array.
Micro-Wave Imager Radiometer Antennas Configurations
Alfredo Catalani (Space Engineering, Italy); Laurent Costes (Airbus Defence and Space/ADS, France); Alessandro Esposito (Space Engineering, Italy)
MWI (Micro Wave Imager) is a multi-channel microwave radiometer which will be embarked on the next MetOp-SG mission aimed to provide cloud and precipitation observations as well as water vapour and temperature gross profiles. MetOp-SG includes two series of three satellites, embarking a total of 10 different instruments. The present paper provides a general description of the MWI antenna design and its performance. As it is well known, the antenna system has an important role for both the radiometric accuracy and the spatial resolution of the instrument, since it has to guarantee at the same time very good beam efficiency and high spatial resolution. . The antenna is able to operate over the frequency range between 18 GHz and 200 GHz, split in eight main frequency bands, each one receiving up to 5 channels as defined by the user requirements.
Wideband Circularly-Polarized 3-bit Transmitarray Antenna in Ka-Band
Fatimata Diaby (Université Grenoble-Alpes & CEA, France); Antonio Clemente (CEA-LETI Minatec, France); Luca Di Palma (Space Engineering S.p.A., Italy); Laurent Dussopt (CEA, LETI, Minatec, France); Kien Trung Pham (Ho Chi Minh City International University, Vietnam); Erwan Fourn (INSA of Rennes & IETR, France); Ronan Sauleau (University of Rennes 1, France)
This paper describes the design of a Ka-band 3-bit circularly-polarized transmitarray antenna. The array is based on a unit-cell composed of two U-shaped slot loaded patch antennas, which are connected by a metallized via hole and printed on two identical dielectric substrates. A 400-element transmitarray is simulated and demonstrates a maximum gain of 27.5 dBi, an aperture efficiency of 47.8%. The 1-dB gain-bandwidth (LHCP) corresponds to 14.8% at 29 GHz. The 1-dB axial ratio bandwidth covers the frequency band between 27 - 32 GHz. A good agreement is obtained between the full-wave simulation results performed with Ansys HFSS and the ones obtained using our hybrid in-house simulation tool. The impact of phase quantization on the performance of a 40×40-element array is also presented. The corresponding radiation patterns (co- and cross-polarization components) are compared to the masks defined by the European International Standardization Institutions (ETSI) in the case of point-to-point applications.
Structured Surface Design to Generate Any Beam Pattern at THz Frequencies
Fabien Defrance (California Institute of Technology, USA); Massimiliano Casaletti (Sorbonne Universités UPMC, France); Julien Sarrazin (University of Pierre & Marie Curie UPMC, France); Martina Wiedner (Observatoire de Paris - LERMA, France); Hugh Gibson (Gibson Microwave Design EURL, France); Gregory Gay (Observatoire de Paris - LERMA, France); Roland Lefèvre (ELORPrintTec, France); Yan Delorme (Observatoire de Paris - LERMA, France)
An iterative alternate projection-based algorithm is developed to design structured surfaces able to generate any far-field beam pattern at GHz and THz frequencies. To validate the algorithm, two structured profiles (a reflective one and a transmissive one) are designed to generate four beams of similar intensity at 610 GHz. The two prototypes are fabricated and tested to experimentally evaluate their performance. Experimental measurements confirm a good agreement with computer simulations using Feko and, therefore, validate the method.
Wideband Circularly Polarized Triangular-Ring Slot Antenna for GAIA-I Microsatellite
Asif Awaludin (Chiba University & Indonesia National Institute of Aeronautics and Space, Japan); Josaphat Tetuko Sri Sumantyo (Chiba University, Japan); Steven Gao (University of Kent, United Kingdom (Great Britain)); Cahya Santosa (Chiba University, Indonesia); Mohd Zafri Baharuddin (Universiti Tenaga Nasional, Malaysia)
A novel compact size equilateral triangular ring-slot antenna is proposed for microsatellite. The presented antenna utilizes truncation, perturbation, and slits to generate wideband circular polarization (CP) operation from its inherited linear polarization. The fabricated antenna has wide CP performance of 1106 MHz or 52.27% of fractional bandwidth at 2116 MHz center frequency. The measured results show that the antenna is bidirectional with its RHCP operation is radiated in main lobe. There is good agreement between simulated and measured radiation patterns.
Genetic Algorithm Application on a Tightly Coupled Array Antenna
Iman Farhat (University of Malta, Malta); Kristian Zarb Adami (University of Oxford, United Kingdom (Great Britain)); John Abela and Charles Sammut (University of Malta, Malta)
A synthesis of a genetic algorithm (GA) and an electromagnetic software (EM) application to guide the design and optimisation of tightly coupled phased array antennas is presented. This technique is biased to satisfy certain desired specifications subject to the mid-frequency SKA radio astronomy. Tightly coupled arrays are a practical realisation of the current sheet model~(CSA) for an array with a wideband characteristic. However, the analysis aims for an optimal impedance matching response. Technically, the EM programme computes the electrical property of the antenna design in implemented MATLAB optimisation loop. The design is verified using both simulations and measurements of a manufactured prototype. A wide bandwidth was achieved exceeding the design specifications set out.
Waveguide Septum Polarizer Shaped with Legendre Polynomials
Jean-Christophe Angevain (ESA, The Netherlands); Nelson Fonseca (European Space Agency, The Netherlands)
This paper presents the design and performance of a contoured septum waveguide polarizer where the longitudinal profile of the septum blade is shaped with Legendre polynomials. A performance comparison with a conventional septum polarizer based on a blade with a stepped profile is performed at Ka-band (27.5 - 30.0 GHz) to show the merit of the proposed profile shaping. Preliminary results indicate an increase in frequency bandwidth of about 20% combined with a length reduction of 5.5%. This compact 3-port waveguide device can be used to generate either dual-circular or dual-linear tilted polarization.
Wideband Pyramidal Sinuous Antenna for Reflector Antenna Applications
Nicol Steenkamp and Dirk de Villiers (Stellenbosch University, South Africa); Ngoy Mutonkole (University of Stellenbosch, South Africa)
This paper presents a wideband pyramidal sinuous antenna, over a conducting ground plane, for use as a reflector antenna feed. Specific attention is given to comparisons with a similar structure where the sinuous shape is instead projected onto a cone. The pyramidal structure is significantly simpler to manufacture, and measured results confirms this where close agreement with simulations is observed.
Electromagnetic Analysis of High Frequency Radomes for Ground Stations in Polar Regions
Andrea Martellosio, Marco Pasian and Luca Perregrini (University of Pavia, Italy); Luca Piffer and Roberto Riccardi (FDS ITALY, Italy); Filippo Concaro (European Space Agency, Germany); Pier Mario Besso (Esa – Esoc, Germany)
At lower frequencies the radome design for ground stations can be considered consolidated, and the microwave transparency can be often obtained with minimal compromises on the structure stiffness. Conversely, at K-band frequencies and above the two domains, electromagnetics and mechanics, require a joint design to achieve best performance, especially when installations at environmentally extreme locations are required. Notably, next generation satellites for Earth Observation, aimed to provide large amount of data exploiting high frequencies, require ground stations at Polar latitudes, where the combination of high-speed winds and low temperature is particularly severe. This paper provides a comparison between two possible solutions for the radome suitable for this kind of installation. In particular, both the transparency of radome walls and the Induced Field Ration of radome interconnections are evaluated. As a test case, a radome to be installed in Svalbard for a European Space Agency ground station is discussed.
Circularly-Polarized Leaky-Wave Antenna at Ka-Band
Darwin Blanco and Ronan Sauleau (University of Rennes 1, France)
A novel low profile circularly-polarized (CP) leaky-wave antenna (CP-LWA) is introduced while the simplicity of the linearly-polarized (LP) primary feed is maintained. The proposed antenna uses a broadband polarizer above a classical LWA. The achieved axial ratio (AR) is kept below 2 dB within a bandwidth of 31$\%$ ranging from 26.7 GHz to 35.5 GHz. All results are verified via full-wave simulations over an angular variation of $\pm$41 deg.
Easy-to-Deploy LC-Loaded Dipole and Monopole Antennas for Cubesat
Korbinian Schraml (RWTH Aachen University, Germany); Adam Narbudowicz (Dublin Institute of Technology, Ireland); Suramate Chalermwisutkul (King Mongkut's University of Technology North Bangkok & The Sirindhorn International Thai-German Graduate School of Engineering, Thailand); Dirk Heberling (RWTH Aachen University, Germany); Max James Ammann (Dublin Institute of Technology, Ireland)
This paper proposes a new approach to reduce weight and complexity of VHF/UHF cubesat antennas by utilizing a dual band antenna, rather than standard two-antenna system routinely implemented in cubesats. Three systems are compared: A standard system with separate transmit/receive dipoles, a dual-band dipole for both transmit and receive and a dual-band monopole, which uses the body of 1U cubesat (10 × 10 × 10cm) as a "groundplane". Additionally it is demonstrated that with appropriate feed the dipole might be used in monopole configuration in case of deployment system malfunction.
Comparison of a Four Stage Sequentially Rotated Wideband Circularly Polarized High Gain Microstrip Patch Array Antennas at Ku-Band
Roshin Rose George and Alejandro T Castro (San Diego State University, USA); Satish K. Sharma (San Diego State University & San Diego State University, USA)
Two sequentially rotated, four stage, wideband circularly polarized high gain microstrip patch array antennas at Ku-band are investigated and compared by incorporating both unequal and equal power division based feeding networks. Four stages of sequential rotation is used to create 16×16 patch array which provides wider common bandwidth between the impedance matching (S11 ˂ -10dB), 3dB axial ratio and 3dB gain of 12.3% for the equal power divider based feed array and 13.2% for the unequal power divider based feed array in addition to high polarization purity. The high peak gain of 28.5dBic is obtained for the unequal power division feed based array antennas compared to 26.8dBic gain in the case of equal power division based feed array antennas. The additional comparison between two feed networks based arrays reveals that the unequal power divider based array antennas provide better array characteristics than the equal power divider based feed array antennas.
SAR Array Synthesis for Next Generation Earth Observation Systems
Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy); Marco Salucci (ELEDIA Research Center, Italy); Angelo Gelmini (ELEDIA Research Center, University of Trento, Italy); Lorenzo Poli, Paolo Rocca and Andrea Massa (University of Trento, Italy)
A novel synthesis methodology for fast and robust design of synthetic aperture radar (SAR) arrays for Earth observation is proposed. An innovative integer coding of the discrete problem unknowns (i.e., the magnitude and phase of the array elements in transmission/reception) is introduced to sensibly reduce the dimension of the search space with respect to the standard binary coding and enable the design of large arrangements. Moreover, suitable customizations of the genetic algorithm (GA) operators (i.e., selection, cross-over and mutation) are exploited for an effective exploration of the solutions, by minimizing highly non-linear/unconventional cost functions linked to specific SAR system quality indicators. Some illustrative numerical benchmarks are illustrated in order to verify the effectiveness of the proposed design technique for the synthesis of next generation radars.
Design of Overlapped Sub-arrays for Planar SparseDirect Radiating Arrays
Theodoros Kaifas and Dimitrios G. Babas (Aristotle University of Thessaloniki, Greece); John Sahalos (Aristotle University of Thessaloniki, GR, Thessaloniki & University of Nicosia, CY, Nicosia, Greece)
In the current work we focus on sparse array design employing overlapping radiating elements. In this case, the underlying sparse grid shapes the broadside directivity farfield pattern while the overlapping flat-top producing subarrays eliminate the scanning loses. In detail, when overlapping arrays are involved the design process is as follows: Perform broadside design, (not scanning beam), using elements' size that keeps Grating Lobes just out of the Field of View (FoV). Since we use Flat-top elements their directivity is reduced and thus their number and/or their size should be increased to balance the two directivity trends. If the element number increase in the previous step is lower than the respective increase due to scanning losses when employing non-overlapping arrays, (and non-Flat-topped element), then we have an accepted solution; In most of the cases, this means that using overlapping we achieve a remarkable reduction in the number of control points.
Wideband High-Efficiency Unit-Cell for 1-bit and 2-bit Transmit-Arrays Operating in X-Band
Hamza Kaouach (LATIS - National Engineering School of Sousse, Tunisia)
A new attractive elementary cell is proposed for 1-bit and 2-bit transmit-arrays in X-Band, where the wideband and low loss characteristics are crucial. The proposed unit cell consists of two identical square patch antennas include C-loop slot and interconnected in their centers by a metalized via hole. The unit cell exhibits a simple three-layer metallic structure and allows standard printed-circuit board fabrication technology. The elementary cell is designed and verified using finite element method simulation. A waveguide measurement system (WGMS) has been utilized for S-parameters characterization. An excellent agreement has been obtained between the simulations and the measurements in terms of impedance matching (S11<-10dB for the range 9.39 GHz -10.26 GHz, 8.8% around 9.85 GHz) and insertion loss (0.36 dB at 9.85 GHz). The proposed unit cell is an excellent candidate for a 1-bit active cell by integrating two PIN diodes in the order to control its transmission phase.
A Study of Wideband Reflectarray Antenna Using Ring-Style Resonator Elements
Takeshi Shiode (Mitsubishi Electric Corporation, Japan); Kento Takeshima and Shigeru Makino (Kanazawa Institute of Technology, Japan); Michio Takikawa, Yoshio Inasawa and Hiroaki Miyashita (Mitsubishi Electric Corporation, Japan)
A wideband design method for reflectarray antennas with conventional ring-type resonator elements is proposed. It is shown that the one of the causes of the narrow bandwidth is the inadequate attenuation of higher order Floquet modes in the substrate. As the dielectric substrate thickness increase, the more the higher order modes are attenuated. Therefore, the substrate thickness is the important parameter for wideband reflectarray antennas. The condition of the substrate thickness for wideband characteristic is shown, and the validity is verified by analyzing reflectarray antennas.
Reflectarray Element Analysis Based on Generalized Sheet Transition Conditions
Xiao Liu, Fan Yang, Maokun Li and Shenheng Xu (Tsinghua University, P.R. China)
The surface electric and magnetic susceptibilities and the surface impedance of an array composed of periodic scatterers are derived based on generalized sheet transition conditions. Using these characteristic parameters, the reflection coefficient of a reflectarray element can be readily computed for arbitrary incident angles, polarizations, and frequencies. The detailed procedure is described and its validity is demonstrated through comparisons with full wave simulations.
A Circuit-Driven Design Methodology for a Wideband Linear-To-Circular Polarizer
Mehdi Hosseini and Sean V Hum (University of Toronto, Canada)
The paper presents a design methodology to achieve a wideband circular polarizer with a relatively low thickness of one-fifth of a free-space wavelength. A three-layer planar structure is devised to exhibit transparency to both TE and TM polarized fields while imparting a quadrature phase difference between them, as required for the generation of circularly-polarized fields. The structure is designed using a circuit-driven approach whereby an independent equivalent circuit describes the behavior of each constituent polarization. Meanwhile, the small unit cell size endows the structure with a low sensitivity to the angle of incidence of the impinging waves. This polarizer with a unit cell volume of 0.13λ0×0.13λ0×0.21λ0 renders axial ratios of less than 3dB and 1dB over ~25% and 9% fractional bandwidths, respectively. Numerical simulations verify the accuracy of the circuit-driven approach and its applicability as a design tool in the synthesis of this class of polarizer.
A Portable Measurement Setup for Characterizing Circular Polarization Selective Structures
Andreas Ericsson, Daniel Sjöberg and Johan Lundgren (Lund University, Sweden)
We present a measurement procedure to characterize the transmission and reflection properties of a circular polarization selective structure using linearly polarized antennas in a portable measurement setup. By applying careful alignment when assembling the setup, together with certain post processing techniques, the circular polarization scattering of a device under test can be accurately determined, both in transmission and reflection.
Design of Planar Metallic Microwave Lenses for Multiple Spot-Beam Systems
Hon Ching Moy-Li and Daniel Sanchez-Escuderos (Universidad Politécnica de Valencia, Spain); Eva Antonino-Daviu and Miguel Ferrando-Bataller (Universitat Politècnica de València, Spain)
This paper presents a microwave planar lens formed by a multilevel frequency selective surface (FSS) aimed at increasing the gain of a radially-corrugated horn antenna. The FSS is formed by three layers of square loops with open stubs. The phase compensation is achieved by shifting the resonant frequency of the unit cell. To do so, only the length of the stubs is suitably adjusted, leaving the rest of geometrical parameters unaltered from one cell to another. Results show an increment of 3.5 dB at 20.1 GHz in the directivity of the planar lens with respect to the feeding horn antenna.
Complementary Metaresonators Based X-Band Hollow Waveguide Filter and Crack Detection Sensor
Safiullah Khan (Technical University of Munich, Germany); Thomas F. Eibert (Technical University of Munich (TUM) & Chair of High-Frequency Engineering (HFT), Germany)
A new metamaterial based subwavelength resonators configuration for X-band hollow waveguides is proposed and its application as a filter and crack detection sensor is discussed. The structure is composed of a complementary rectangular split ring resonator embedding a T-type resonator. The filter has a 0.9 GHz bandwidth at 9.11 GHz resonance frequency. The comparison between a perfect surface and a defected surface is presented and observations are made using signal comparisons. Around the resonance frequency the signal comparison shows the difference in the reflection behavior for both the surfaces when the width and the depth of the crack are varied. The technique can be extended to study the material characteristics of different media.
Integration of Resistive Heaters for Phase-Change Reconfigurable Antennas
Dimitris Anagnostou (Heriot-Watt University (UK), United Kingdom (Great Britain)); David Torres (Michigan State University, USA); George Goussetis and Symon K. Podilchak (Heriot-Watt University, United Kingdom (Great Britain)); Tarron Teeslink and Nathan Kovarik (South Dakota School of Mines and Technology, USA); Nelson Sepulveda (Michigan State University, USA)
Vanadium dioxide has recently been proven successful as a mechanism of reconfiguration of an antenna. We present and discuss the integration of resistive heaters underneath the surface of the vanadium dioxide thin film, on the antenna wafer. These resistive heaters are important for the implementation of a biasing mechanism that is fast (in the range of microseconds) and that does not couple electromagnetic energy to the antenna structure. Results of antennas with and without the integrated heaters, along with additional applications of this technology will be presented and discussed.
Land-mobile X-band Satellite Measurements in Norway, Experiment Description and First Results
Vegard Arneson (FFI, Norway); Lars Erling Bråten (Norwegian Defence Research Establishment (FFI), Norway); Jostein Sander, Terje Mikal Olsen Mjelde and Oystein Olsen (FFI, Norway)
Findings from a vehicular satellite communication experiment at X-band along a 5460 km route in Norway was described in this paper. The elevation angle was between 10° in the North and 20° in the South. System availability, coverage and excess attenuation on a 7.25 - 7.75 GHz down-link from a geostationary satellite was found by measuring a satellite beacon. The purpose of the experiment was to investigate possibilities and challenges by utilizing vehicular satellite communications. It was found that the average availability of the time was 61.4 %. The average coverage of the distance was 56.1 %. Based on map data and measured GPS positions, the calculated fraction of distance with line of sight visibility to the satellite was 84 % and the vegetation shadowing was about 28 % of the total distance. Significantly better coverage requires alternatives such as diversity of satellites providing higher elevation angles.
Combined Beacon and Noise Satellite Propagation Measurements Using Software Defined Radio
Apostolos Z. Papafragkakis and Athanasios D. Panagopoulos (National Technical University of Athens, Greece); Spiros Ventouras (STFC Rutherford Appleton Laboratory, United Kingdom (Great Britain))
Considering the imminent migration of services to the Ka- and Q- bands, a payload dedicated to propagation measurements in these bands has become available from the Alphasat satellite under the coordination of the European Space Agency. This has strongly motivated the formation of many measurement campaigns across Europe in an effort to enhance the scientific databases with new, more reliable propagation data. In the framework of our campaign at the National Technical University of Athens (NTUA) in Greece two identical beacon receivers targeting the Alphasat's Ka-band beacon were designed and deployed; these receivers make use of the relatively new Software Defined Radio (SDR) paradigm. Apart from the beacon measurements themselves, additional noise measurements are performed to supplement the campaign. The present paper constitutes an attempt to outline the characteristics and associated advantages of this methodology over the conventional techniques.
Analysis of One-Year Data of Slant Path Rain Attenuation at 19 and 39 GHz in Prague
Martin Grabner (Czech Metrology Institute, Czech Republic); Ondrej Fiser (Institute of Atmospheric Physics & Fac. of Electrical Engineering and Informatics/Uni of Pardubice, Czech Republic); Viktor Pek (Institute of Atmospheric Physics CAS, Czech Republic); Pavel Pechac (Czech Technical University in Prague, Czech Republic); Pavel Valtr (Faculty of Electrical Engineering, Czech Technical University in Prague, Czech Republic)
Attenuation time series measured on the satellite-to-ground path in Prague in frequency bands 19 and 39 GHz and simultaneously measured rain intensity are analyzed statistically using one-year dataset. Frequency scaling is described by linear models. Empirical power law models are fitted to the measured data directly and to the obtained annual cumulative distributions. Monthly statistics obtained shows the worst months in terms of rain attenuation. Fade slope and fade duration cumulative distributions are determined and discussed.
High-Order Evaluation and Modelling of Cross-Polarization Discrimination on Earth-Satellite Propagation Paths at Ka and V-Bands
Flávio M. da Silva Jorge (Instituto de Telecomunicações & Universidade de Aveiro, Portugal); Carlo Riva (Politecnico di Milano, Italy); Armando Rocha (University of Aveiro & Instituto de Telecomunicações, Portugal)
The SatComs performance employing frequency-reuse schemes to improve the spectral efficiency is degraded due to the depolarization-induced interference originated by hydrometeors present along the propagation path. Two models are able to account for all contributions: one enables the prediction of the first-order statistics (CDF) of cross-polarization discrimination (XPD), and another enables the prediction of the relationship between XPD and co-polar attenuation (CPA). The second was developed for the V-band and so, it requires independent validation and extension to other frequency-bands. The predictions provided by the first are usually converted on the corresponding XPD-CPA relationship using the long-term first-order statistics of rain attenuation, (wrongly) considering that the equiprobability base applies. Using 8 years of measurements both models are tested, a new regarding the XPD-CPA relationship is proposed for the Ka-band and another base to be employed on the conversion of the CDF of XPD on the XPD-CPA relationship is investigated.
Alphasat Experiment at Aveiro: Data Processing Approach and Experimental Results
Joel Flávio (Universidade de Aveiro, Portugal); Armando Rocha (University of Aveiro & Instituto de Telecomunicações, Portugal); Susana Mota (University of Aveiro & Institute of Telecommunications, Portugal); Flávio M. da Silva Jorge (Instituto de Telecomunicações & Universidade de Aveiro, Portugal)
The execution of propagation campaigns monitoring satellite beacons and assessing the Earth-satellite propagation channel is a demanding task, but absolutely necessary to deploy successfully future communication satellites operating at Q-band and above, where highly demanding satellite services can be offered given the wide bandwidth available at those frequency-bands. These campaigns require very high equipment availability, accurate measurements and careful data preprocessing to get time series of high quality for modelling purposes. A large campaign is now being executed all over the Europe using the Alphasat satellite. Here we describe the experimental arrangement in Aveiro-Portugal, we report on some equipment tests that have been performed, and present an innovative approach to the preprocessing software. Finally, a few results (event based and statistical outputs) already obtained are also discussed.
Joint Results of the Aveiro and Vigo Alphasat Propagation Campaigns
Joel Flávio (Universidade de Aveiro, Portugal); Fernando Pérez-Fontán (University of Vigo, Spain); Flávio M. da Silva Jorge (Instituto de Telecomunicações & Universidade de Aveiro, Portugal); Susana Mota (University of Aveiro & Institute of Telecommunications, Portugal); Armando Rocha (University of Aveiro & Instituto de Telecomunicações, Portugal)
The usage of Fade Mitigation Techniques (FMT) is mandatory for satellite communications over 10 GHz once the atmospheric propagation effects get severe with the increase of the frequency-band. Site Diversity (SD) and Orbital Diversity (SD) are two effective techniques to mitigate rain attenuation. Considering an operation at Q-Band (40GHz), in this paper a SD scheme comprising the Aveiro and Vigo earth stations, located 177km apart, is exposed and an OD configuration, with an aperture angle of 18º at Aveiro, is preliminary investigated.
Annual Statistics of the Alphasat Ka and Q-band Propagation Channel in Budapest, Hungary
László Csurgai-Horváth and Bernard Adjei-Frimpong (Budapest University of Technology and Economics, Hungary)
The Alphasat telecommunication satellite was launched in July, 2013 and beside of the main payload it carries four scientific experiments. One of them is the Aldo Paraboni Scientific Experiment, a propagation experiment in the Ka and Q radio bands. The experiment is coordinated by the European Space Agency under the framework of ARTES 8 Telecom program. Hungary, similarly to other European experimenters established a receiver station in Budapest for each beacon transmitter channels of the satellite. This project was supported and financed by the European Space Agency. Our purpose was to record long time received power level time series of the Ka and Q-band satellite channel among relevant meteorological data as well. The station is operating with its full functionality since mid-2015 and the data collected so far permits the calculation of yearly attenuation statistics, demonstrating the monthly variations and allowing the comparison with relevant ITU-R statistics as well.
Experimental Analysis of Passive Intermodulation at TNC Coaxial Connectors
Rui Wang (National Key Laboratory of Science and Technology on Space Microwave, P.R. China); Wanzhao Cui (China Academy of Space Technology Xi'an, P.R. China); Chen Xiang (Xi'an Institute of Space Radio Technology, P.R. China); Chunjiang Bai (NKLSTSM, P.R. China); Na Zhang (China Academy of Space Technology (Xi’an), P.R. China); Yun Li (China Academy of Space Technology Xi an, P.R. China)
In this paper, the generation of passive intermodulation at standard TNC coaxial connectors is investigated. A series of tests has been performed in order to analysis the intermodulation level under different temperature circumstances. The relationship between the intermodulation response of the connectors and the change of temperature and straining on the junctions has been studied. It has been found that the passive intermodulation of TNC coaxial connectors was very sensitive to the changes of temperature and straining. High intermodulation should be caused when warming up from the low temperature.

### Wednesday, March 22, 13:30 - 16:20

#### SWS_03: Nanotechnology Applications of Antennas and Wireless Sensing

WG Meetings & WorkShops: Room 315
Chairs: Krishna Naishadham (Georgia Institute of Technology, USA), Patrizia Savi (Politecnico di Torino, Italy)

### Wednesday, March 22, 15:00 - 16:20

#### Inv_03 Invited Session 3

Room: Oral Sessions: Auditorium Bordeaux
Chairs: Michael Jensen (Brigham Young University, USA), Manuel Sierra-Castañer (Universidad Politécnica de Madrid, Spain)
15:00 Channel Modeling for Dependable Vehicular Connectivity
Christoph F Mecklenbräuker (Vienna University of Technology, Austria)
Vehicles and other road users will be linked to each other and the road infrastructure to make traffic more efficient, cleaner, and safer. For example, Vehicle-To-Vehicle (V2V) and Vehicle-To-Infrastructure (V2I) communication enables cooperation and intelligent route management in transport networks. To achieve these ambitious goals, wireless links must become dependable: The information relevant for intelligent transport systems (ITS) shall be shared reliably within a tolerated latency. Challenges for cooperative ITS are posed by nonstationary time-frequency-selective fading processes in vehicular channels. Fortunately, the nonstationary vehicular fading may be characterized by assuming local stationarity for a finite region in the time-frequency plane. Thus, we characterize the channel by a local scattering function (LSF). High delay spreads are observed for rich scattering and high Doppler spreads characterize drive-by scenarios. These channel characteristics translate into packet error sequences exhibiting dependencies. Finally, we discuss packet error models of low complexity for large-scale cooperative ITS emulation.
15:40 Overview of OTA Testing of 5G Enabled Devices
Philippe Garreau (Microwave Vision Group, France)
The promise of 5G and internet of things (IoT) is a future in which an inconceivable number of everyday devices are connected with incredible speeds. 4G was the first mobile system actually designed with global standardization. This was one of the key factors in the success of 4G and the speed of its deployment. Today, the main objective of the communication community is to realise common standards for 5G and build a global system. The deployment of test systems at various prestigious events will then follow. The 2018 Winter Olympics in Korea and the 2020 Summer Olympics in Japan are examples of such pilot systems. Finally, users will have 5G devices and will enjoy the full performance of this new technology. We know that test and measurements of 5G enabled devices and base-stations will differ widely from what we are doing today. 5G implies higher and widely available spectrum at frequencies up to 100GHz, which can accommodate the implementation of Massive-MIMO involving multiple small antennas and in-device processing. This will move the emphasis from the antenna towards system testing. Important parameters, determined from conducted testing for 4G, will likely be performed in Over-The-Air (OTA) setups in tomorrow's 5G. This puts a strong requirement on the measurement industry to provide effective testing solutions to developers, industries and regulators. As testing technology, the very effective multi-probe systems have evolved with the development of 1 to 4G technology in the last 25 years. It is today a reference for OTA testing of such devices. While concepts such as testing in near and far field (NF, FF) is less critical in current 1-4G standardisation, NF testing and NF performance of devices is likely to be a critical issue for 5G. In this paper/presentation we will give an introduction to existing measurement technology and a vision on the evolution of testing technology for 5G enabled devices.

#### Inv_04 Invited Session 4

Room: Oral Sessions: Auditorium Havane
Chairs: Joel Lemorton (ONERA, France), Fernando Pérez-Fontán (University of Vigo, Spain)
15:00 Antenna Technologies for Spaceborne SAR
Pasquale Capece (Thales Alenia Space Italia, Italy)
The Presentation will provide an overview of the most significant Space Antennas for spaceborne SAR systems both based on planar aperture and on reflector systems. Active phased array architecture will be presented with focusing on RF aspects, digital distribution and power subsystem. Thermo-mechanical aspects will be also considered and discussed. An overview of the technologies used for radiating elements, TR modules and beam forming will be reported. Technology for Reflector antennas will be also presented including benefits and drawbacks vs planar systems.
15:40 The Characterization of the Atmospheric Radio Channel for Satellite Services, an Overview of ESA Activities
Antonio Martellucci (European Space Agency, The Netherlands)
The effects of the propagation of radio waves in the atmosphere can be relevant for a number of Satellite services, including Satellite Communication (SatCom) systems, Global Navigation Satellite Systems (GNSS), Earth Exploration and Space Exploration systems. In particular the lower part of the atmosphere (i.e. the troposphere and to some extent also the stratosphere) induces several propagation effects, including attenuation, depolarisation, signal scintillation, noise emission, excess path length. These effects are relevant in all phases of a Space project, including preliminary and final design, in-orbit tests and operations. The effect of atmospheric propagation on Satellite services becomes more relevant as technological developments opens new frequency bands (see evolution of SatCom frequency bands from C up to W band), improves the performances of system components making more critical for the link budget the random contribution of atmospheric propagation or the system requirements impose a trade-off between system performances and system margins (e.g. between maximisation of data throughput and minimisation of system unavailability). In this framework the criteria for system design and control have to evolve from a classical static approach towards flexible and adaptive methodologies. This implies also the need to improve channel assessment techniques and to minimise the error of experimental measurements.This talk will present an overview of developments and channel modelling used by the European Space Agency in the framework of a number of ESA projects, including the Alphasat Aldo Paraboni (TDP5) experiment for SatCom services at Q/V band, contribution to Radio Regulations (ITU-R SG3), the development of models of tropospheric error for Galileo GNSS and its evolution, the use of Ka band for Earth Exploration missions (like METOP-SG) and support to radioscience experiments of Space Exploration missions (like Bepi-Colombo and JUICE, to Mercury and Jupiter).

#### IWS_04: Efficient simulation of antenna placement on different platforms (Aeronautical, Automotive, Naval,...)

WG Meetings & Workshops: Room 313/314
Chair: Eddy Jehamy (Altair FEKO, France)

### Wednesday, March 22, 16:50 - 18:30

#### Sp_A03 Reflectarrays and Transmitarrays

Space / Regular Session / Antennas
Room: Oral Sessions: Auditorium Bordeaux
Chairs: Dirk de Villiers (Stellenbosch University, South Africa), Paolo Rocca (University of Trento, Italy)
16:50 Experimental Characterization of Dual Linearly Polarized Transmitarray Antennas At X-Band
Trung Kien Pham (University of Rennes 1 & IETR, France); Ngoc Tinh Nguyen (University of Nice Sophia Antipolis, France); Laurent Le Coq (University of Rennes 1 & IETR, France); Ronan Sauleau (University of Rennes 1, France); Antonio Clemente (CEA-LETI Minatec, France); Laurent Dussopt (CEA, LETI, Minatec, France)
This paper presents the detailed experimental characterization of X-band 400-element transmitarray antennas in dual linear polarization. The latter can radiate two different and independent beams in two distinct directions with orthogonal polarizations. Two prototypes are designed and fabricated at 10 GHz; one with two beams radiating at boresight, and one designed for two beams pointing in a different direction in each polarization. A 3-dB gain bandwidth of 20% is reached for both polarizations and maximum gain is over 25 dBi for broadside beam.
17:10 Tolerance Analysis of the Reflectarray Antenna Through Minkowski-based Interval Analysis
Nasim Ebrahimi and Nicola Anselmi (ELEDIA Research Center, Italy); Paolo Rocca and Andrea Massa (University of Trento, Italy)
Having a robust architecture against tolerances is one of the most important aspects in high frequency antenna design. In this paper, the effect of fabrication errors on the power pattern of reflectarray antenna is investigated. The uncertainty on the actual size of the patch width is modeled with the interval values. The rules of Interval Arithmetic are then exploited to compute the bounds of the deviation in the resonance frequency, the reflection phase of each element and the radiated power pattern. Due to the redundancy of the Interval Analysis in complex domain, Minkowski sum is implemented to perform the summation. We show that the Minkowski-based Interval Analysis can produce a narrower and inclusive bound. To guarantee the validity of the model, a Monte Carlo test has been carried out to cover the Interval- Minkowski bounds.
17:30 Loss Analysis of a Reflectarray Cell Using ANNs with Accurate Magnitude Prediction
Vincent Richard (Institut d'Electronique et de Télécommunications de Rennes, France); Renaud Loison and Raphael Gillard (IETR & INSA, France); Hervé Legay (Thalès Alenia Space, France); Maxime Romier (CNES, France)
This paper proposes a design methodology to improve the Artificial Neural Networks modeling of reflectarray cells with regards to the prediction of reflection coefficients magnitude. It is applied to model both types of RA cells (capacitive and inductive) with 5 inputs parameters. The results demonstrate that the final ANNs models are reliable and accurate with an average error on the reflection coefficient magnitude of the scattering matrix (|R11|) of -66dB and -69dB respectively for the capacitive and inductive cells. This accurate prediction of magnitude allows rejecting a priori any cell with loss exceeding a prescribed threshold. Comparison of two canonical reflectarray layouts shows the benefit that could be expected in a synthesis process.
17:50 Design of a 24 GHz Reconfigurable Transmitarray Element with Continuous Phase Range
Martin Frank (University of Erlangen-Nuremberg & Institute f. Electronics Engineering, Germany); Robert Weigel (Friedrich-Alexander Universität Erlangen-Nürnberg & Eesy-id, Germany); Alexander Koelpin (Brandenburg University of Technology & Chair for Electronics and Sensor Systems, Germany)
This paper presents a reconfigurable transmitarray antenna unit-cell for a frequency of 24 GHz. A continuous phase range is obtained by loading patches with varactor diodes on the outer layers of a printed circuit board (PCB) while the signal couples through slots in the inner layers. The design, numerical and experimental characterization of the unit-cell in a rectangular WR-42 waveguide are reported. A phase tuning range of 120° was achieved with a custom layer stack which could be extended to 145° using solely RF-substrates.
18:10 A Single Layer Stub-Patch Phoenix Cell for Large Band Reflectarrays
Hassan Salti (Australian College of Kuwait, Kuwait); Raphael Gillard (IETR & INSA, France)
A novel Phoenix cell for large band reflectarray antennas is presented here. The cell starts with a simple square patch whose phase shift is controlled by its sides' length. The size of the patch is then fixed and open-stubs with variable length are connected to it. To complete the phase range at the central frequency, the stub-loaded patch then shrinks gradually until it disappears completely allowing the cell to rebirth. The cell is characterized by a phase range of 360˚ at the central frequency, linear phase responses with respect to frequency and a reduced phase dispersion of less than 34˚/GHz within a 40% bandwidth. The suggested cell retains the same bandwidth when accounting for incidence angles of up to 30˚ and a reduced bandwidth of 32% accounting for higher incidence angles of up to 45˚.

#### CS21 Innovative Antenna Architectures for Very High Throughput Satellite (VHTS) Systems

Space / Convened Session / Antennas
Room: Oral Sessions: Auditorium Havane
Chairs: Nelson Fonseca (European Space Agency, The Netherlands), Baptiste Palacin (CNES, France)
16:50 VHTS Systems: Requirements and Evolution
Hector T. Fenech (Eutelsat S.A., France); Sonya Amos (Eutelsat, France); Antonin Hirsch (Eutelsat SA, France); Viphakone Soumpholphakdy (Eutelsat S.A., France)
EUTELSAT's first HTS system, KA-SAT is still the largest in Europe and very often a benchmark. Since then EUTELSAT has launched EUTELSAT 36C to deliver services over Russia and EUTELSAT 65A over LATAM. BB4A is currently under production to provide services over Africa. The requirements for HTS systems evolve and are mainly driven by economics trying to drive the cost of per unit capacity lower to remain attractive and gain new applications. The paper looks at the salient evolution of the requirements as HTS system evolve into VHTS.
17:10 Multibeam Antennas for Very High Throughput Satellites in Europe: Technologies and Trends
Baptiste Palacin (CNES, France); Nelson Fonseca (European Space Agency, The Netherlands); Maxime Romier and Romain Contreres (CNES, France); Jean-Christophe Angevain (ESA, The Netherlands); Giovanni Toso and Cyril Mangenot (European Space Agency, The Netherlands)
This paper proposes an overview of recent CNES and ESA developments related to broadband satellite applications. Ka-band multi-beam antennas for user links and Q/V-band antennas for feeder links are crucial components to cope with stringent VHTS mission requirements. A brief presentation of technical trends since early 2000 is exposed with a specific focus on multi-beam antenna technology. Also, the main needs for upcoming VHTS systems and the key developments needed to increase significantly the overall system capacity of current satellites while maintaining total system cost competitive are presented.
17:30 Ka-Band User Antennas for VHTS GEO Applications
Yves Demers (MDA Corporation, Canada); Eric Amyotte (MDA, Canada); Karim Glatre (MDA Corporation, Canada); Marc-André Godin (MDA, Canada); Jonathan Hill (MDA Corporation, Canada); Aiping Liang and Mathieu Riel (MDA, Canada)
Very High Throughput Satellite (VHTS) user antennas with their large number of beams and very large beam scans present several new design challenges. One of these challenges is to control scan aberrations as they lead to high scan losses, low C/I and ultimately, lower capacity. This paper presents a comparison between the results of various array-fed reflector antenna designs that are considered for VHTS missions.
17:50 Antenna Developments for Geostationary VHTS Satellites at Airbus Defence and Space
Simon J Stirland (Airbus Defence and Space Ltd); Michael Schneider (Airbus, Germany); Steve McLaren (Airbus Defence and Space Ltd)
In recent years there has been an accelerating trend towards increasing numbers of Ku- and Ka-band beams in geostationary telecommunications satellites. In the near future it is expected that we will see requirements for several hundred if not thousands of such beams for the next generation of VHTS satellites. This will require a step change in antenna architectural design but equally importantly component level RF design as well as thermal and mechanical design. This paper provides an overview of developments in these areas in Airbus Defence and Space.
18:10 Application of Bifocal Concept to Dual Reflectarray Configurations for Multi-Beam Satellite Antennas in Ka-Band
Eduardo Martinez-de-Rioja and Jose A. Encinar (Universidad Politecnica de Madrid, Spain); Antonio Pino and Borja Gonzalez-Valdes (University of Vigo, Spain); Carolina Tienda (Airbus Defence and Space, United Kingdom (Great Britain)); Sean V Hum (University of Toronto, Canada); Giovanni Toso (European Space Agency, The Netherlands)
This contribution describes the design of a multi-beam dual reflectarray antenna for operation in transmission in Ka-band (20 GHz). The bifocal design concept has been used to obtain an improved performance for the off-axis beams with respect to the single focused antenna. The required phase-shift distributions are initially obtained with the reflectarrays in parallel planes, and then adjusted to compensate the tilting of both reflectarrays in the final Cassegrain configuration. The simulated radiation patterns in the elevation and azimuth orthogonal planes have been calculated for the two beams generated by the focuses, and then the multi-beam performance of the antenna has been evaluated.

#### W_P01 Vehicular channels

Wireless Networks / Regular Session / Propagation
Oral Sessions: Room 341
Chairs: Philippe Besnier (IETR, France), Davy P Gaillot (University of Lille 1, France)
16:50 Polarimetric Ground-to-Ground and Ground-to-Air Channel Characterization in Forest Environment
Pierre Laly (University of Lille, France); Davy P Gaillot (University of Lille 1, France); Martine Liénard (University of Lille, France); Jean-marie Floch (IETR-INSA Rennes, France); Rose Mazari and Pierre Degauque (University of Lille, France); Guy Grunfelder (IETR-INSA De Rennes, France)
The precise localization of an injured person in a forest environment can be made owing to his cell phone by deploying a dedicated direction finding equipment in the search zone and placed onboard either a vehicle or a drone. The localization accuracy being strongly dependent on the propagation channel characteristics, measurements have been carried out with a MIMO channel sounder at a center frequency of 1.35 GHz and with an 80 MHz bandwidth. Each array element is a dual-polarized patch antenna allowing a multidimensional polarimetric estimation of the channel. The receiving array is below or over the canopy when onboard a vehicle or at different altitudes when onboard a drone. Path loss, delay spread and coherence bandwidth are studied for different relative orientations of the antennas, including co- and cross-polarization configurations. Directions of arrival of the rays are deduced from the MIMO matrix owing to a high resolution algorithm.
17:10 Simulation of V2V Communications in Various Propagation Channels: Assessing Antenna Performance in Terms of PER
Jessen Narrainen (IETR - INSA de Rennes & Renault SAS, France); Philippe Besnier (IETR, France); Philippe Boutier (Renault sas, France)
In this paper, we present a simple and complete simulation approach to compare antenna performance within the frame of Vehicle-to-Vehicle (V2V) communication systems. A geometry-based stochastic channel model (GBSCM) is used to simulate propagation channel pertaining to main environments in a V2V context. Once propagation scenarios are simulated, they are combined with the integration of various antenna locations and patterns. Finally, their performance can be analyzed in terms of Bit Error Rate (BER) or Packet Error Rate (PER) after the implementation of the physical layer (PHY layer) following the IEEE 802.11p standard dedicated to V2X communications.
17:30 Cluster-Based Radio Channel Emulation for Over-the-Air Testing of Automotive Wireless Systems
Philipp Berlt, Frank Wollenschläger and Christian Bornkessel (Technische Universität Ilmenau, Germany); Matthias Hein (Ilmenau University of Technology, Germany)
More and more radio systems are incorporated in modern automobiles e.g. multiple mobile communication standards for car-to-car or car-to-infrastructure communications like LTE, ITS G5, satellite navigation, radar detection, and so on. These complex systems need to be tested extensively and under realistic conditions. This paper discusses a modular approach for antenna constellations for over-the-air tests in the virtual road simulation and test area (VISTA) of the Thuringian Center of Innovation in Mobility at the Technische Universität Ilmenau. The goal is to reproduce multipath clusters, in terms of the angular spread of arrival and, as a consequence, the spatial correlation of received signals, as a key parameter of mobile communication channels. This paper amplifies the scope of current research on modular antenna configurations and analyzes the influence of array design parameters on the spatial correlation and, hence, on their suitability for reliable channel emulation.
17:50 RCS Modeling and Measurements for Automotive Radar Applications in the W Band
Emna Bel Kamel and Alain Peden (Telecom Bretagne, France); Patrice Pajusco (TELECOM Bretagne, France)
This paper describes a reliable methodology for radar cross section (RCS) measurement of complex small and large targets in the W band. The backscattering behavior of a small car model was measured in an anechoic chamber along with various automotive related targets in a wide gymnasium. Experimental performance in the anechoic chamber is compared to the simulation results. Our simulation model is based on deterministic scattering centers, determined by high frequency approaches, like the physical optics (PO) and the physical theory of diffraction (PTD). Nevertheless, simulations of realistic large objects are both time consuming and difficult to implement. The proposed measurement configuration enables the extraction of non-predetermined scattering points for large object modeling which will significantly decrease the simulation time for road scenarios in radar applications.
18:10 A New Method for Evaluation of LTE MIMO Antennas in Automotive Application
Mahmoud Almarashli (Universität der Bundeswehr München, Germany); Stefan Lindenmeier (Universität der Bundeswehr, Germany)
For the LTE standard using multiple-input multiple-output (MIMO) radio-access technology, there is a high challenge to evaluate car antennas appropriately, taking into account the antenna environment formed by the car body in the MIMO channel. New statistical methods are required on base of the propagation properties of antennas which are integrated close to each other in a reflecting and refracting environment. In this contribution we present an evaluation method of LTE-car antennas, which enables the analysis of virtual drives. The test drives are performed via simulation of driving paths in urban or rural environments with ray-tracing, while the description of the receiving part is given via the complete information of the complex antenna characteristics of the coupled antennas which are measured on a real car. An example with two realized antenna modules is analyzed by this method and the results are compared to results from real drives.

#### C_P02 Indoor Propagation

Cellular Communications / Regular Session / Propagation
Oral Sessions: Room 342A
Chairs: Iñigo Cuiñas (University of Vigo, Spain), Wout Joseph (Ghent University/IMEC, Belgium)
16:50 Characterization of Wireless Propagation Through Traditional Iberian Brick Walls
David Ferreira (University of Vigo & Instituto de Telecomunicações, Portugal); Telmo R. Fernandes (IPLeiria / Institute of Telecommunications & ESTG/IT-DL, Portugal); Rafael F. S. Caldeirinha (IPL - Polytechnic Institute of Leiria & Instituto de Telecomunicação (IT), Portugal); Iñigo Cuiñas (University of Vigo, Spain)
This paper presents the wireless transmission properties for brick walls with different thicknesses and facade finish coatings. The ceramic hollowed bricks under study are traditionally employed in the Iberian residential construction, where the 11, 15 and 20 cm thicknesses are most common in indoor and outdoor walls. For each brick dimension, three different prototypes were manufactured varying in the type of wall finish, i.e.: naked brick, smooth painted plaster and rough painted plaster. The prototypes were measured in an anechoic chamber at frequencies ranging from 680MHz up to 10GHz. Results demonstrate that the brick wall internal heterogeneity, as well as the type of finish, significantly influence the frequency response of the walls.
17:10 Channel Estimation Using Spherical-wave Model for Indoor LoS and Obstructed LoS Scenarios
Yilin Ji, Wei Fan and Gert Pedersen (Aalborg University, Denmark)
When the array apeture increases to a huge extent (e.g. tens to hundreds of wavelengths), and the distances between transmitter, scatterers, and receiver are small, conventional plane-wave model cannot be used to characterize the impinging wave accurately anymore. To avoid model mismatch during estimation, in this paper, we use spherical-wave model as the generic signal model, and estimate parameters of multipath component (MPC) with a maximum likelihood method for indoor line-of-sight (LoS) and Obstructed LoS (OLoS) scenarios. The estimated MPCs are reconstructed in the physical environment using a simple geometric method. Comparison with plane-wave model was also conducted to investigate the necessarity of spherical-wave model.
17:30 Polarimetric Properties of Indoor MIMO Channels for Different Floor Levels in a Residential House
Sunil Raut Kshetri (Ghent University & Imec, Belgium); Emmeric Tanghe (Ghent University, Belgium); Davy P Gaillot (University of Lille 1, France); Martine Liénard (University of Lille, France); Luc Martens (Ghent University, Belgium); Wout Joseph (Ghent University/IMEC, Belgium)
This paper analyzes polarimetric characteristics of power delay profiles, cross polarization discrimination (XPD), and received power of specular and diffuse multipath components of MIMO radio channels at 2.45 GHz. Measurements were done in a residential house at two floors levels: same floor'' and cross floor''. Variations of 5 to 15~dB in PDPs between co-and cross-polar links were found in the same floor level; however these changes decrease as links go from line-of-sight to non-line-of-sight. XPDs of the radio waves were found to be higher for the cross floor configuration, about 5~dB in horizontally and 7~dB in vertically polarized waves. Also, diffuse components of the radio channels were less affected in cross-polar subchannels compared to that of specular components in the same floor level. The results demonstrate the contribution of diffuse components to the total channel power is higher than previously presented studies for indoor environments.
17:50 Doppler Characteristics for Indoor Mobile-to-Mobile Channels
Gloria Makhoul (CEA-LETI & ICTEAM Electrical Engineering, Université Catholique de Louvain (UCL), France); Francesco Mani (Università degli studi di Bologna, Italy); Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France); Claude Oestges (Université Catholique de Louvain, Belgium)
This paper analyzes Doppler spectra of mobile-to-mobile (M2M) channels, based on a measurement campaign carried out in an indoor environment at 2.48 GHz. The Doppler spectra are characterized in line-of-sight (LOS) and non-line-of-sight (NLOS) environments for different types of pedestrian movements. Subsequently, an analytical Doppler spectrum model is proposed and successfully compared to the measurement data.
18:10 Measurement and Modeling of 3-Dimensional Radio Channels with Cross-Polarizations in a Gymnasium
Zhimeng Zhong (Huawei Technologies Co., Ltd., P.R. China); Ruonan Zhang, Kaijun Ren and Kun Wang (Northwestern Polytechnical University, P.R. China); Bin Li (Northwesten Polytechnical University, P.R. China); Xiaomei Zhang (Huawei, P.R. China)
Directional beamforming can increase the network capacity significantly with spatial multiplexing, especially for the hot spots such as airport, shopping malls, and stadiums. Accurate characterization and models of the spatial propagation in such indoor environments are required. In this paper, a 3-dimensional MIMO channel measurement campaign in a large gymnasium is presented. A wideband sounder equipped with two dual-polarized crossed linear arrays was used and the transceivers were placed at different positions on the stands. The azimuth and elevation power spectrum and root-mean-square angular spread of arrival (ASA/ESA) of the multipath components were measured. The normal and lognormal distribution models are proposed for the angular power spectra and angular spreads, respectively. Finally it is demonstrated that the angular spreads have no tendency with respect to the transceiver positions. The measurement results can support the design of the directional transmission technologies for spatial multiplexing in indoor hot-spot scenarios.

#### CS50 Wireless Sensors for Medical Applications: from Wearables to Implants

Biomedical / Convened Session / Antennas
Oral Sessions: Room 342B
Chairs: Konstantina Nikita (National Technical University of Athens, Greece), Raed Shubair (Massachusetts Institute of Technology (MIT), USA)
16:50 Wireless Sensors for Medical Applications: Current Status and Future Challenges
Hadeel Elayan (Khalifa University, United Arab Emirates); Raed Shubair (Massachusetts Institute of Technology (MIT), USA); Asimina Kiourti (The Ohio State University, USA)
Continuous health monitoring using wireless body area networks of implantable and wearable medical devices is envisioned as a transformative approach to healthcare. Rapid advances in biomedical sensors, low-power electronics, and wireless communications have brought this vision to the verge of reality. However, key challenges still remain to be addressed. This paper surveys the current state-of-the-art in the area of wireless sensors for medical applications. It focuses on presenting the recent advancements in both wearable and implantable technologies. Furthermore, this paper addresses the challenges that exist in the various Open Systems Interconnection (OSI) layers and illustrates future research areas concerning the utilization of wireless sensors in healthcare applications.
17:10 A Polarization/Frequency Interchangeable Patch for A Modular Wearable Textile Antenna
Shengjian Jammy Chen and Damith C. Ranasinghe (The University of Adelaide, Australia); Christophe Fumeaux (The University of Adelaide & School of Electrical and Electronic Engineering, Australia)
A concept of modular textile antennas based on commercial snap-on buttons has been recently proposed for wearable applications. This concept has been demonstrated to provide passive system reconfigurabilities in resonance frequency, polarization and/or radiation characteristics using a common feeding structure as a base. In this paper, as a further illustration of the versatility of the modular concept, a circular patch module with a rectangular flap cut in the middle is proposed. This module can provide interchangeability between right-handed circular polarization (RHCP), left-handed circular polarization (LHCP) and linear polarization (LP), as well as passive reconfigurability in resonance frequency for LP, through simple module rotation and different flap configurations (opened or closed).
17:30 Performance Evaluation and Sensitivity Analysis of a Novel Rectenna System for Deep Implanted Devices
Sofia Bakogianni, Mihalis Palaiologos and Stavros Koulouridis (University of Patras, Greece)
We examine the performance of an implantable antenna combined with a rectifier circuit (Rectenna) in terms of polarization stability, effect of surrounding tissue electrical properties and implantation depth. A single-layer Planar Inverted F-Antenna (PIFA) that exhibits dual-resonance for data telemetry (MedRadio band, 402 MHz) and power transfer (ISM band, 915 MHz) is employed. Antenna polarization is investigated through axial ratio computations. Further, we consider nine tissue-dielectric scenarios comprising ±5% and ±10% variations in the initial tissue permittivity and conductivity. Subsequently, the antenna implantation depth is, also, altered. Indeed, proposed implantable antenna is robust with regards to reliability of wireless link, resonance response and radiation performance. Finally, an improved, previously presented, rectifier system is presented. As shown, its efficiency reaches almost 40% (20% increase) for an optimum load RL=9.5 kOhm at a reference power level Pr=-16 dBm.
17:50 Energy Harvesting and Cardiovascular Monitoring Through Arterial Wall Pulsation
Grigorios Marios Karageorgos, Christos Manopoulos, Socrates Tsangaris and Konstantina Nikita (National Technical University of Athens, Greece)
In this paper, we present an optimized design of an energy harvesting device that converts the arterial wall pulsation to electrical energy and we demonstrate its feasibility to function as a sensor for cardiovascular system monitoring. The device is based on electromagnetic induction and is composed of a coil that pulsates with the artery inside the magnetic field produced by two permanent magnets. In order to validate the proposed concept and evaluate the device's performance, an experimental setup that mimics blood flow and arterial wall movement was constructed. In-vitro experiments indicated that proper optimization can increase the device's produced power and voltage, and that the output voltage of the coil is associated with heart rate, blood pressure, arterial wall velocity and deformation.
18:10 Bio-degradable Material for Short Term Implants
Max Munoz and Emiliano Bilotti (Queen Mary, University of London, United Kingdom (Great Britain)); Yang Hao (Queen Mary University, United Kingdom (Great Britain))
The paper presents some preliminary results of electromagnetic characteristics of a layered bio-degradable material. Measurement data demonstrates that the proposed material can be used as a suitable substrate for design and implementation of compact antennas for applications such as low power autonomous sensors and short-term medical implants.

#### H_A04 Mm-Wave Antennas for High Data Rate II

High Data-rate Transfer / Regular Session / Antennas
Oral Sessions: Room 343
Chairs: Nima Ghalichechian (The Ohio State University, USA), Dirk Manteuffel (University of Hannover, Germany)
16:50 An Improved Millimeter-Wave Bull's Eye Antenna
Konstantinos Konstantinidis (University of Birmingham, United Kingdom (Great Britain)); Despoina Kampouridou (University of Birmingham, UK); Marina Mavridou and Alexandros Feresidis (University of Birmingham, United Kingdom (Great Britain))
In this paper, an improved mm-wave Bull's eye antenna is proposed. The structure is formed by concentric periodic rings etched of a metallic plane. The antenna is designed to produce high-gain radiation patterns with broadband operation around 14 GHz. A novel feeding technique is introduced yielding a broadband input matching performance. The antenna has been simulated using CST Microwave StudioTM, achieving a maximum gain of 15.8 dB and 3 dB bandwidth of 17%. A prototype has been fabricated and the results will be presented.
17:10 High Aperture Efficiency Bull's-Eye Antenna
Unai Beaskoetxea (Universidad Pública de Navarra, Spain); Miguel Beruete (Universidad Publica de Navarra, Spain)
A 60 GHz operating Bull's-Eye (BE) antenna with wide corrugations and a soft-surface is numerically and experimentally analyzed. The employment of wide grooves, rather than narrow grooves, allows a high enhancement of the gain, whereas the inclusion of the soft surface, reduces the side lobe level as well as the backward radiation. A BE with narrow corrugations was also simulated for the purpose of comparison. Fabricated antenna shows a gain of 20.3dB which, due to its reduced dimensions, corresponds to a high aperture efficiency ea = 32%. Furthermore, -13.2 dB side lobe level and 10.4 deg beamwidth are observed.
17:30 Additive Manufactured Millimeter Wave Off-Axis Bull's-Eye Antenna
Unai Beaskoetxea (Universidad Pública de Navarra, Spain); Stefano Maci (University of Siena, Italy); Miguel Navarro-Cía (University of Birmingham, United Kingdom (Great Britain)); Miguel Beruete (Universidad Publica de Navarra, Spain)
Despite their low profile and competitive radiation characteristics, most of the devices in the corrugated leaky wave antenna family feature an unnecessary excess weight which result detrimental for current innovative applications, such as unmanned aerial vehicles (UAV), aircrafts or satellite antennas. Stereolitography, accompanied by plating, is presented as an economic and fast solution for the manufacturing of lightweight devices, which at the same time is able to overcome traditional metal drilling/spark erosion manufacturing limitations. Here we present an elliptical Bull's-Eye antenna operating at 96 GHz fabricated following a 3D-printing and copper coating process. Due to the off-centered grooves, a tilted beam pointing at 16.5º is obtained, presenting a gain of 17 dB and 3.5 beamwidth.This prototype results of interest for point-to-point communications where direct front side view is not possible, as well as for applications where lightweight and cost-effective antennas are needed, such as satellite communications or deployed in UAV's.
17:50 60 GHz 3D Integrated Waveguide Fed Antennas Using Laser Direct Structuring Technology
Aline Friedrich (Leibniz Universität Hannover, Germany); Malte Fengler (LPKF Laser & Electronics AG, Germany); Bernd Geck (Leibniz Universität Hannover, Germany); Dirk Manteuffel (University of Hannover, Germany)
The following contribution presents the design of waveguide fed antennas that are directly integrable into injection molded plastic parts using 3D molded interconnect devices technology. The fabrication method used for 3D metallization of the plastic parts is Laser Direct Structuring (LDS). First a single dielectric filled waveguide fed horn antenna is developed, fabricated and characterized to verify the LDS process. The results show a good match between simulated and measured data proving the principle suitability of the LDS process. Based on this the approach of integrating this type of antenna directly into plastic parts is discussed. As an example a dielectric horn antenna is integrated into a generic plastic part and evaluated based on field simulations. The antenna is developed to operate in the frequency range of the WiFi IEEE 802.11ad standard.
18:10 60 GHz Capacitively Probe-Fed Patch Arrays with Suspended Elements
Kaveh Keshtkaran (The Ohio State University & Electroscience Laboratory, USA); Nima Ghalichechian (The Ohio State University, USA)
A major drawback of current millimeter wave technologies used for integration of phased arrays on a chip is low efficiency (5-10%) and consequently low realized gain. In this work, we present integrated antenna arrays on silicon that exhibit radiation efficiency of >80% at 60 GHz. This is achieved by suspending the radiating elements of a phased array in air using micro-electro-mechanical (MEMS) processes, effectively replacing a lossy silicon substrate (under each element) with air. In the latest design we used capacitive feeding with pin and patch height of 40 and 60 µm, respectively. Finite element simulation results verify the performance of the array. A finite array with 5×5 elements achieved -10-dB bandwidth of 1.7 GHz. Array is well matched at 60 GHz with S11<−19 dB. Maximum realized gain (at broadside) is 20 dBi with sidelobe level of -13.3 dB. The efficiency is calculated to be 89%.

#### CS40 Radiation Control Techniques for Small Antennas

Future Applications / Convened Session / Antennas
Oral Sessions: Room 351
Chairs: Christophe Delaveaud (CEA-LETI, France), Richard W. Ziolkowski (University of Arizona, USA)
16:50 Meta-atom Based Dielectric Ferrite Antennas for 3D Printing
J (Yiannis) Vardaxoglou (Loughborough University, United Kingdom (Great Britain))
This paper examines the effect of the dielectric and magnetic properties of meta-atom artificial materials and how these properties affect the overall performance of small antennas. These structures could be manufactured with 3D printing.
17:10 Non-Foster Impedance Design Techniques for High Performance Small Antenna
Deepak Nagarkoti and Khalid Z Rajab (Queen Mary University of London, United Kingdom (Great Britain)); Yang Hao (Queen Mary University, United Kingdom (Great Britain))
The non-Foster impedance circuits enhance the bandwidth performance of small antennas. This paper explores various conventional and novel techniques to realise non-Foster impedance and conclude their advantages as well as limitations. These design techniques includes conventional operational amplifiers (op-amps) and bipolar junction transistors (BJTs) and non-conventional graphene field-effect transistors (GFETs) and resonant tunnelling diodes (RTDs). This paper facilitate the designer to select the appropriate non-Foster circuit (NFC) for broadband matching of antenna.
17:30 Decoupling Approach of Superdirective Antenna Arrays
Abdullah Haskou (IETR UMR CNRS 6164, Université de Rennes1, France); Ala Sharaiha (Université de Rennes 1 & IETR, France); Sylvain Collardey (University of Rennes 1, France)
The inter-element distance in superdirective arrays is usually very small and hence the mutual coupling is considerably high. Consequently, these arrays present relatively low efficiencies. In this paper, we propose using decoupling techniques for reducing the mutual coupling, and hence increasing the efficiency, in this kind of arrays. The concept is proven by full wave simulations of two different Electrically Small Antenna (ESA)-based two-element arrays with an inter-element distance of 0.1λ. In the first array with a ka = 0.56, the original (before decoupling) radiation efficiency of 7% is increased to 13.4% and the realized gain is increased from −6.4dBi to −2.6dBi. In the second array with a ka = 1.18, the original radiation efficiency of 52.1% is increased to 63.7% and the realized gain is increased from 3dBi to 3.9dBi.
17:50 Superdirective Radiation of Arrays of Thin-Wire Nanoloops
Mario F Pantoja (University of Granada, Spain); Jogender Nagar and Bingqian Lu (The Pennsylvania State University, USA); Douglas H Werner (Pennsylvania State University, USA)
Superdirective radiation is one of the most challenging and elusive problems in electromagnetics because of its inherent drawbacks, such as the narrowband and extreme sensitivity. However, there is a renewed research interest on the superdirectivity problem to solve the problem of the short-range communications of nanodevices. This contribution presents recent advances based on arrays of thin-wire nanoloops, aimed to explore the possibilities of these structures as seed of nanodevices which can bring to the reality a wideband, superdirective radiation patterns at the terahertz and infrared regimes. Potential applications are remote sensing, wireless communications and nanoelectronics.
18:10 Implementation of a THz Quasi-Spiral Antenna for THz-IR Detector
Alicia E. Torres-García (Public University of Navarra, Spain); Iñigo Ederra (Universidad Pública de Navarra, Spain); Ramon Gonzalo (Public University of Navarra, Spain)
A sub-millimeter quasi-spiral antenna based on a modified Fresnel Zone Plate Lens (FZPL) for the IR range is proposed. The design is part of an integrated receiver, which consists of a Si (silicon) slab where two detector configurations will be printed working at infrared (IR) and sub-millimeter range simultaneously. Various modifications of spiral antennas are evaluated to act as a sub-millimeter wave antenna (operating at 700 μm) and as a modified Fresnel Zone Plate Lens in the Mid-IR range (around 10.6 μm). The design, optimization and fabrication process for the quasi-spiral antenna with the best performance for both functions are presented.

#### R_P02 Radar Systems

Radars / Regular Session / Propagation
Oral Sessions: Room 352A
Chair: Jochen Moll (Goethe University Frankfurt am Main, Germany)
16:50 Calibration of a Fully Polarimetric 8x8 MIMO FMCW Radar System at 77 GHz
Tristan Visentin and Juergen Hasch (Robert Bosch GmbH, Germany); Thomas Zwick (Karlsruhe Institute of Technology (KIT), Germany)
State-of-the-art millimeter wave (MMW) multiple-input, multiple-output (MIMO) frequency-modulated continuous-wave (FMCW) radars allow high precision direction of arrival (DOA) estimation with an optimized antenna aperture size [1]. Typically, these systems operate using a single polarization. Fully polarimetric radars on the other hand are used to obtain the polarimetric scattering matrix (S-matrix) and extract polarimetric scattering information that otherwise remains concealed [2]. Combining both approaches by assembly of a dual-polarized waveguide antenna and a 77GHz MIMO FMCW radar system results in the fully polarimetric MIMO radar system presented in this paper. By applying a MIMO-adapted version of the isolated antenna calibration technique (IACT) from [3], the radar system is calibrated and laboratory measurements of different canonical objects such as spheres, plates, dihedrals and trihedrals are performed. A statistical evaluation of these measurement results demonstrates the usability of the approach and shows that basic polarimetric scattering phenomena are reliably identified.
17:10 Activity Monitoring of Bats in a Laboratory Flight Tunnel Using a 24 GHz FMCW Radar System
Jochen Moll and Moritz Mälzer (Goethe University Frankfurt am Main, Germany); Viktor Krozer (Goethe University of Frankfurt am Main, Germany); Dimitry Pozdniakov (HF Systems Engineering GmbH & Co. KG, Germany); Rahmi Salman (HF Systems Engineering GmbH & Co. KG & Hübner Holding GmbH, Germany); M. Jerome Beetz and Manfred Kössl (Goethe University Frankfurt am Main, Germany)
Radar techniques have been used recently to monitor bats when they are hunting close to wind energy plants. However, the real-time detection of bats is a challenge and activity metrics must be defined that enable a robust bat detection. In this paper we report on FMCW radar measurements at 24 GHz of Seba's short-tailed fruit bats (Carollia perspicillata) in a laboratory flight tunnel. Experiments have been performed with a single flying bat and multiple simultaneously flying bats. We introduce several activity metrics and discuss their properties. Further signal processing results, such as Range-Doppler maps, will be presented and discussed.
17:30 Multipath Estimation Technique for Wideband mm-Wave Backscattering Channels
Francesco Guidi (CEA LETI, France); Antonio Clemente (CEA-LETI Minatec, France); Raffaele D'Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France)
In this paper we describe a method to discriminate multipath components in joint angular and temporal domain by exploiting the a-priori knowledge of the antennas characteristics into an ad-hoc algorithm for wideband backscattering channels. By means of two indoor measurement campaigns performed using millimeter-waves massive arrays in a corridor and in an office room, we show the feasibility of the proposed approach and we compared its performance to those of methods already available in the state of the art.
17:50 Experimental Comparison of Localisation Techniques in the Presence of Array Uncertainties
Qinxin Liu and Athanassios Manikas (Imperial College London, United Kingdom (Great Britain))
In this paper, the performance of two source localization (range and azimuth) approaches are studied experimentally using multiple off-the-shelf Universal Software Radio Peripheral (USRP) hardware boards forming a circular antenna array of nine elements operating in the presence of a source located in the near-far field of the array. In particular, the effects of gain and phase array uncertainties on these localization approaches are presented and their experimental accuracy is examined in terms of both range and direction RMSE.
18:10 A Novel Processing Algorithm for Multiple Elevation Beam SAR Systems
Taoli Yang (UESTC, P.R. China); Donglin Li (Shanghai Institute of Satellite Engineering, P.R. China)
A novel processing algorithm for multiple elevation beam (MEB) synthetic aperture radar (SAR) systems is presented. MEB SAR is a promising technique to reduce the onboard data amount, and its key processing procedure is subpulse separation which is affected by the topography. In this paper, the echoes received by multiple elevation channels (MEC) are regarded as signals coming from different direction-of-arrive (DOA) angles. Then, the subpulse separation is transformed to DOA estimation. Considering the sparsity of the received signals in spatial domain, the sparse-based DOA estimation algorithm is adopted. After obtaining the DOA angles, the overlapped subpulses are separated. The algorithm can also be applied to other MEC SAR systems. Finally, the effectiveness of the proposed algorithm is confirmed in simulations.

#### L_A01 Antenna sensors

Localization & Connected Objects / Regular Session / Antennas
Oral Sessions: Room 352B
Chairs: Etienne Perret (Grenoble INP - LCIS, France), Patrizia Savi (Politecnico di Torino, Italy)
16:50 Wireless Monitoring of Breath by Means of a Graphene Oxide-based Radiofrequency Identification Wearable Sensor
Maria Cristina Caccami and Mohammad Yusuf Shafi Mulla (University of Rome "Tor Vergata", Italy); Corrado Di Natale (Università di Roma Tor Vergata, Italy); Gaetano Marrocco (University of Rome Tor Vergata, Italy)
The monitoring of the breathing dynamic characteristics, including the presence of biomarkers in exhaled breath, is of growing interest in noninvasive diagnosis of diseases. We describe a wearable radiofrequency identification (RFID) device hosting a flexible antenna suitable for integration into a facemask and a sensor made of graphene oxide sensitive to the humidity variations. The so obtained wearable wireless sensor was characterized in reference conditions and was then experimentally demonstrated to be capable of detecting the inhalation/exhalation cycles and abnormal patterns of respiration like the apnea by measuring the changes in graphene oxide resistance.
17:10 RFID Helix Antenna on Power Cord for the Sensing of Home Electrical Devices Activity
Rupesh Kumar, II (Technicolor & Research & Innnovation, France); Ali Louzir and Jean-Yves Le Naour (Technicolor, France)
a flexible RFID-Helix antenna wrapped around the power-cord, integrated with a RFID tag and a current impulse detection circuit, for wireless sensing of the activity of home electrical devices, is proposed. While the use of a straight dipole showed a significant distortion of the antenna radiation pattern due to the very close proximity of the wires inside the power cord, the use of a helical dipole reduces significantly the coupling to the power cord. Furthermore, the antenna coupling to the impulse current arising at the switch ON/OFF of the electrical device, required by the application, is improved and the overall size of the antenna reduced. A realized prototype of the impulse sensing RFID tag using the designed helix-dipole antenna wrapped around the cord demonstrated a sensing range of 7-8 m with a standard RFID reader operating in the US 915 MHz RFID band.
17:30 Potential of Chipless Authentication Based on Randomness Inherent in Fabrication Process for RF and THz
Zeshan Ali (Grenoble INP - LCIS); Florent Bonnefoy (University of Savoie Mont Blanc, IMEP-LAHC, France); Romain Siragusa (Grenoble INP - LCIS); Nicolas Barbot, David Hély and Etienne Perret (Grenoble INP - LCIS, France); Maxime Bernier and Frédéric Garet (University of Savoie Mont Blanc, IMEP-LAHC, France)
In this paper, two chipless solutions dedicated to the authentication of manufactured products are proposed. One device is operating in the RF domain while the other used terahertz (THz) waves. The concept of chipless RFID is extended to authentication where each tag has to present a unique signature that can never be reproduced even if someone try to copy the tag. Both approaches use Electromagnetic (EM) wave as a tool for non-invasive and non-destructive authentication of items. The results show that it is possible to discriminate RF, respectively THz, signatures obtained from devices whose differences of geometrical parameters are as small as tens of micrometers, respectively several micrometers in the THz domain.
17:50 Design of a Graphene-Loaded Slotted Ring Resonator for Sensor Applications
Patrizia Savi (Politecnico di Torino, Italy)
Graphene is a monolayer of carbon atoms with remarkable electronic and mechanical properties amenable to sensor applications. While the plasmonic nature of graphene at terahertz frequency has been widely reported, investigations on the practical utility of graphene at the microwave frequencies used in wireless sensor nodes are sparse. In this paper, a printed RF slot ring resonator is configured with a graphene thin-film for sensor application. The graphene sensing element comprising the slot ring can be integrated with control electronics as a passive wireless sensor node, but the sensor aspect is not addressed in this paper. The novelty of the paper is that RF losses are minimized by capacitively loading the ring at selective locations along its periphery. Dielectric spectroscopy is used to study variation in surface impedance of the film for various graphene loadings, and RF simulations are corroborated with measurements on graphene loaded slot ring resonators.
18:10 An Electromagnetic Sensing System Incorporating Multiple Probes and Single Antenna for Wireless Structural Health Monitoring
Burak Ozbey and Ayhan Altintas (Bilkent University, Turkey); Hilmi Volkan Demir (Nanyang Technological University, Singapore); Vakur Erturk (Bilkent University, Turkey); Ozgur Kurc (Middle East Technical University, Turkey)
In this study, a wireless and passive displacement/ strain sensing system is proposed for structural health monitoring (SHM). The wireless and passive interrogation of the sensing unit [a variant of a nested split-ring resonator (NSRR)] is achieved through the near-field interaction and electromagnetic coupling between the single antenna in the system and the multiple sensors called the NSRR probes. It is demonstrated that the system can acquire data from more than one NSRR probe simultaneously in a real-life scenario, where the probes are confined within concrete inside a beam, while the antenna monitors them from outside.

#### MT_M01 Advances in Test Range Design

Methods & Tools / Regular Session / Measurements
Oral Sessions: Room 353
Chairs: Bernd Gabler (German Aerospace Center (DLR), Germany), Bengt Svensson (Saab AB, Sweden)
16:50 Full-Wave Analysis of a Compact Antenna Test Range Including Probe Effect
Thomas M Gemmer, Rasmus Cornelius, Joerg Pamp and Dirk Heberling (RWTH Aachen University, Germany)
Simulated Quiet Zone (QZ) performance of a designed Compact Antenna Test Range (CATR) is validated by QZ field probing. Simulations of CATRs, however, lack of modeling the probe. The receiving antenna which is used in order to evaluate the field in the QZ has an influence on the calculated / measured co- and cross-polar components. The degree of the effect depends on the radiation characteristic and on the cross-polarization purity of the probe. Including the probe into simulations overcomes the disadvantages of probe correction since the possibility exists to calculate arbitrary dimensions of the QZ. To determine the extent, three probes are characterized and used during field-probing measurements at a frequency of 4.5 GHz. Subsequently, simulated QZ data is generated using a single-reflector model in combination with the multi-level fast multipole method implemented in FEKO. The measured probe patterns are included into the calculated data by applying planar near-field theory.
17:10 Modular Simulation of a Compact Antenna Test Range
Björn Möhring (Technical University of Munich (TUM), Germany); Markus Limbach, Bernd Gabler and Alberto Di Maria (German Aerospace Center (DLR), Germany)
This paper presents a method for the modular simulation of a Compact Antenna Test Range (CATR). The CATR simulated in this work is similar to the installed facility at the Microwaves and Radar Institute at the German Aerospace Center (DLR) in Oberpfaffenhofen and it has a dual reflector configuration. A model of this facility was created and simulated with both full-wave methods such as Method of Moments (MoM) and asymptotic methods such as Iterative Physical Optics (IPO) by means of the software tool Antenna Design Framework (ADF). The implemented method is used to gather insights of the working principle of this chamber, to provide data in order to judge real obtained measurement results, and to draw out weaknesses of this CATR.
17:30 Measurement of a Large Radome at an Antenna Compact Test Range
Bengt Svensson (Saab AB, Sweden); Bjorn Widenberg (GKN Aerospace Applied Composites, Sweden); Mattias Viberg (Saab AB, Sweden)
A 5 m SATCOM radome has been measured at the Saab A15 compact test range. The modifications of the test range, such as including the gimbal axes in the measurement system, are described. Furthermore, different measurement considerations, due to the large sized radome, are discussed and highlighted. Some typical results are also shown. The range was found to have very small drift and excellent repeatability.
17:50 A New Compact Antenna Test Range for EW-Antenna System Production Testing
Bengt Svensson and Rikard Gustafsson (Saab AB, Sweden); Peter Hultman (Saab Electronic Defence Systems, Sweden); Per-Åke Hansson and Christian Augustsson (Saab AB, Sweden); Anders Jernberg (MVG Seden); Carsten Seupel (Orbit/FR, Sweden)
A new Compact Antenna Test Range, for EW-antenna system production measurements, is presented. The test object is an active, complex antenna system with several low-gain elements as well as an AESA. The focus in the design of the range was to be able to handle efficient production measurements for this advanced, broadband, test object. To facilitate this, the range is highly automated, which makes it possible to measure several frequency bands, Tx/Rx mode, and test object states in an automated sequence. Test object access and handling was also a key parameter in the range design. Special care was taken to minimize disturbances from the turn tables by recessing the azimuth and slide positioners in a pit in the floor. This is especially important for accurate measurements and interferometry calibration of the low-gain antenna elements.
18:10 Design, Fabrication and On-site Alignment of Low-cost Reflector Used in Large-scale Compact Antenna Test Range
Wang Mingming, Li Dongsheng, Zhou Xianbin and He Guoyu (Beihang University, P.R. China)
A low-cost reflector used in large-scale compact antenna test range (CATR) with Φ6.0m quiet zone and 0.5~110GHz operating frequency is developed. Firstly, the geometry dimension, dividing scheme and structure form of the reflector are designed according to electrical requirements. Then, vacuum forming based on reconfigurable discrete nail mould (RDNM) is developed to rapidly and low-costly manufacture high-accuracy reflector with honeycomb sandwich structure. Due to extra-large area, the whole reflector is divided into many small panels to be fabricated separately. Meanwhile, steel framework and adjustment mechanism are designed to install and adjust all these panels. Then, a closed-loop adjustment system is constructed by adjustment mechanism and commercial laser tracker to adjust and align all these panels on site. Through final alignment, the root mean square (RMS) of surface error of the whole reflector comes up to 28?m.

#### F_A02 MetaSurfaces I

Future Applications / Regular Session / Antennas
Oral Sessions: Room 362/363
Chairs: Bertrand Etchessahar (CEA, France), Giacomo Oliveri (University of Trento & ELEDIA Research Center, Italy)
16:50 RCS of Targets with Plasmonic Coatings: Computation, Additive Manufacturing and Measurement
Genevieve Maze-Merceur, Carol Saint-Flour and Bertrand Etchessahar (CEA, France); Fabien Degery (CEA-DAM, France); Pierre Massaloux (CESTA, France); Olivier Vacus (CEA-DAM, France)
Plasmonic coatings could be a solution to the design of stealthy targets over the microwave range. In this communication, Perfectly Electrically Conducting spheres with plasmonic coatings are studied. Two main issues are raised. As the exact computation of the Radar Cross Section (RCS) of finely textured targets with overall dimensions greater than the wavelength of interest often leads to high CPU time consumption, an effective medium approximation correctly describing the electromagnetic behaviour of the coating is suggested. The resulting approximated RCS computations are in good agreement with the exact full wave solution over a broad range of microwave frequencies. Afterwards, a textured spherical metallic target was designed and manufactured. Relying on computer-aided additive manufacturing, a periodically grooved metallic sphere has been realized successfully. Eventually, as we shall see, experimental RCS measurements of a periodically grooved metal sphere and the corresponding theoretical computations compare fairly well.
17:10 Tunable Water-based Microwave Metasurface
Polina Kapitanova and Mikhail Odit (ITMO University, Russia); Dmitry Dobrykh (Dep. of Nanophotonics and Metamaterials, ITMO University, Russia); Andrei Andryieuski (Technical University of Denmark, Greece); Andrei Lavrinenko (Technical University of Denmark, Denmark); Pavel Belov (ITMO University, Russia)
A water-based dynamically tunable microwave metasurface is developed and experimentally investigated. A simple approach to tune the metasurface properties by changing the shape of water-based unit cells by gravitation force is proposed. The transmission spectra of the metasurface for linear and circular polarizations of the incident wave are numerically simulated and experimentally measured under the metasurface rotation around a horizontal axis. The measured changes of the transmission coefficient magnitude up to 8 dB at 1.25 GHz are reported while rotating the metasurface by the 90 degree angle. The proposed approach can be used to design cheap metasurfaces for electromagnetic wave control in the microwave frequency range.
17:30 Decoupling of Dipole Antenna Array on Patch Type Meta-Surface with Parasitic Cells
Yuki Kawakami (National Institute of Technplogy, Fukui College, Japan); Ryuji Kuse, Toshikazu Hori and Mitoshi Fujimoto (University of Fukui, Japan)
A low-profile and decoupling dipole antenna array is achieved by combining patch type meta-surface with proposed parasitic cells. Based on the moment method analysis results, it is clarified that proposed parasitic cells can suppress mutual coupling of dipole antennas without additional impedance. In addition, the maximum decoupling effect of 13.3 dB is achieved.
17:50 Bianisotropic Huygens' Metasurface Leaky-Wave Antenna with Flexible Design Parameters
Elena Abdo-Sánchez (University of Málaga & E. T. S. I. Telecomunicación, Spain); Ariel Epstein (Technion - Israel Institute of Technology, Israel); George V. Eleftheriades (University of Toronto, Canada)
We propose a novel leaky-wave antenna configuration which consists of a parallel-plate waveguide with the top plate being a bianisotropic Huygens' metasurface of the omega type. By using closed-form expressions for the metasurface design and after a valid stipulation of the fields below and above it, we are able to design a passive and lossless metasurface that achieves the desired field transformation. The theoretical formulation highlights that we have practically all possible degrees of freedom in the stipulation of the input and output fields. In this way, several examples show that we can arbitrarily choose the output angle, the constant leakage factor and the waveguide height.
18:10 Aperture Coupled Circularly Polarized Array Antenna in Ridge Gap Waveguide Technology
Xingchao Dong (National Space Science Center & University of Chinese Academy of Sciences, P.R. China); Hongjian Wang (National Space Science Center, P.R. China); Fei Xue and Yang Liu (National Space Science Center & University of Chinese Academy of Sciences, P.R. China)
A 4×1 aperture coupled circularly polarized array antenna in ridge gap waveguide technology is presented. The ridge gap waveguide technology is employed to create a desired directional wave propagation. Circular polarization is obtained by introducing L-shaped slot coupling to an oval shaped patch. The simulated results show high circular polarization purity (axial ratio less than 1dB) over the frequency range of 14.58-15.20GHz and the reflection coefficient of better than -10dB over 14.56-15.25GHz band. Gain and radiation patterns of the proposed array antenna are also provided.

#### WG_05 ESoA

WG Meetings & Workshops: Room 313/314
Chair: Stefano Maci (University of Siena, Italy)

## Thursday, March 23

### Thursday, March 23, 08:40 - 12:30

#### CS41 Recent Developments in Antenna Technologies for Emerging Satellite Systems

Space / Convened Session / Antennas
Room: Oral Sessions: Auditorium Havane
Chairs: Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France), George Goussetis (Heriot-Watt University, United Kingdom (Great Britain)), James Nessel (NASA, USA)
08:40 Wideband Multibeam Arrays of Long Slots Fed by Quasi-optical Systems
Francesco Foglia Manzillo (CEA-LETI, France); Mauro Ettorre (University of Rennes 1 & UMR CNRS 6164, France); Thomas Potelon (IETR - University of Rennes 1, France); Maciej Smierzchalski (CEA, France); Ronan Sauleau (University of Rennes 1, France); Nicolas Capet (CNES, France)
This paper summarizes the latest advances on an innovative, broadband multibeam antenna, proposed for satellite communications by the Institute of Electronics and Telecommunications of Rennes (IETR), in the framework of a collaborative research with the French Space Agency (Centre National d'Etudes Spatiales). The antenna comprises an array of long slots, parallel-fed by a corporate feed network of parallel plate waveguides. An integrated quasi-optical beamformer, illuminated by a single horn or by a focal array of horns, excites the feed network. The beam scanning can be achieved both mechanically and electronically. The numerical models developed for the analysis and design are reviewed. The experimental results presented for a Ka-band design demonstrates the wideband, wide-angle scanning performance of the proposed architecture. Finally, future research lines for achieving circular polarization are projected. The proposed antenna concept is particularly suitable for high throughput ground terminals on moving platforms.
09:00 Preliminary Design of the NISAR L-Band Feed Antenna Tiles
Paolo Focardi (Jet Propulsion Laboratory & California Institute of Technology, USA); Paula Brown (JPL, USA)
Being developed in partnership between NASA and the Indian Space Research Organisation (ISRO), the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite is planned to launch in late 2020. NISAR will measure many aspects of how Earth is changing with unprecedented accuracy on a global scale from a Low Earth Orbit (LEO) platform. With a 12m deployable mesh reflector, NISAR will feature one of the largest deployable mesh reflector ever launched for a scientific mission. Two large planar phased arrays will feed the reflector, one that will operate at L-Band and be developed by the Jet Propulsion Laboratory (JPL), and an S-band array that will be developed at the ISRO Space Application Centre (SAC). This paper describes the preliminary design of the L-Band feed array.
09:20 A Wide Band Wide Scanning Range Multiple Beam Antenna Based on a Radiating Parallel Plate Waveguide Continuous Delay Lens Beamformer
Hervé Legay (Thalès Alenia Space, France); Ségolène Tubau, Etienne Girard and Jean Philippe Fraysse (Thales Alenia Space, France); Ronan Sauleau (University of Rennes 1, France); Nelson Fonseca (European Space Agency, The Netherlands)
A novel multiple beam antenna architecture is proposed based on a quasi-optical lens beamformer. It consists in the combination of a doubly curved reflector with a stack of fully metallic parallel plate waveguide beamformers terminated with a flare. It has the capability to reduce the phase aberration over a large angular sector, and thus to improve the characteristics of radiated multiple beams. A novel quasi-optical beamformer based on a continuous delay lens was designed, manufactured and tested. The wide band and wide scanning capability is demonstrated at Ku band. Low return loss and mutual coupling is also achieved for all input ports. The agreement between measurements and simulations is outstanding, for both the S parameters and the radiation patterns. The beamformer was also designed to operate in the Ka- Rx/Tx band. It is of high interest for on-board antennas for LEO and MEO constellation systems.
09:40 Planar Wide-Scan Wideband Arrays Based on Connected Slots and Artificial Dielectrics
Daniele Cavallo, Waqas Hassan Syed and Andrea Neto (Delft University of Technology, The Netherlands)
In this work we present an antenna concept for wideband and wide-scanning phased array applications. The array unit cell consists of a connected-slot element radiating in the presence of a backing reflector and an artificial dielectric superstrate. The artificial dielectrics have anisotropic characteristics that allows to avoid surface waves and scan blindness over a wide scan range and a large frequency band. The design of a dual-polarized array operating in the bandwidth from 7 to 14.5 GHz is presented. Simulated performance show active voltage standing wave ratio (VSWR) lower than 2.5 for scanning up to 60 degrees in the H-plane and 70 degrees in the E-plane. This array is implemented with a single multi-layer printed circuit board, which represents an advantage in terms of cost and complexity, compared to previous connected-array designs.
10:00 Circularly Polarised Multiple Beam Antenna for Satellite Applications
Wenxing Tang (Heriot-Watt University, United Kingdom (Great Britain)); Daniele Bresciani (Thales Alenia Space, France); Hervé Legay (Thalès Alenia Space, France); George Goussetis (Heriot-Watt University, United Kingdom (Great Britain)); Nelson Fonseca (European Space Agency, The Netherlands)
This paper presents a novel circularly polarised Ku-band multiple beam antenna based on a quasi-optical beamformer and a wideband reflection polarizer conformally deployed along a cylindrical parabolic reflector for satellite applications. By virtue of the wide scanning capability of the beamformer and the wide band and angularly stable response of the curved polarising reflector we demonstrate multibeam capability in circular polarization up to ±18° for a wide Ku band (10-14.5 GHz) with axial ratio below 2 dB. Manufacturing and testing methods are discussed. A breadboard of the multibeam reflector antenna has been fabricated and tested demonstrating very good performance that matches the simulated results.
10:20 Coffee Break
10:50 Ground-Based Antenna Array Phasing Issues and Mitigation for Satellite Communications
James Nessel (NASA, USA)
Communications with satellites in deep space require large antenna aperture systems on the ground in order to receive and transmit data at the power levels necessary to establish a link. However, these large antennas are costly to build and maintain and represent single point failure systems. An alternative to this approach, presently being investigated by NASA, is the use of several smaller aperture antennas combined in an array. The additional difficulty introduced by this approach is the more pronounced impact of atmospheric turbulence which induce phase scintillation errors across the effective aperture of the array. In this paper, the impact of atmospheric-induced phase scintillation on ground based antenna arrays is defined and techniques to mitigate phase scintillation for next generation communications arrays are introduced. A particular focus is made on a novel passive phase scintillation sensing technique utilizing a blind source separation (BSS) approach.
11:10 Prediction of Far-Field Pattern Characteristics of Phased Array Fed Reflector Antennas by Modeling Only a Small Part of the Array - Case Study of Spaceborne Radiometer Antennas
Oleg Iupikov, Artem Roev and Marianna Ivashina (Chalmers University of Technology, Sweden)
In this work we present an approach for the prediction of far-field pattern characteristics of phased array fed reflector antennas by modeling only a small part of the array. In this approach, the simulated EEPs of the FPA are modeled as the phase-shifted versions of the simulated embedded element pattern (EEP) of the central element, and thereafter combined with the optimum weighting coefficients in order to find the total pattern of the feed. Although, the EEPs of dense array antennas are generally not identical (due to the array antenna mutual coupling and edge truncation effects), for typical FPA excitation scenarios, where the array edge elements have relatively low weights to produce the desired illumination of the reflector, this simplified approach has been found sufficiently accurate.
11:30 Present State of Antenna Design for X-band SAR Sensor Onboard 100 Kg Class Satellite
Prilando Rizki Akbar (Institute of Space and Astronautical Science-Japan Aerospace Exploration Agency, Japan); Budhaditya Pyne (University of Tokyo, Japan); Hirobumi Saito (Institute of Space and Astronautical Science-Japan Aerospace Exploration Agency, Japan); Jiro Hirokawa and Dong-Hun Kim (Tokyo Institute of Technology, Japan)
As to realize Synthetic Aperture Radar (SAR) sensor onboard small satellite, a deployable parallel-plate slot array antenna currently has been developed. The propose antenna operates in X-band frequency with vertically polarized radiation. Currently, one antenna panel has been designed by using HFSS simulator. From simulation results, it is expected that antenna with directivity and efficiency of 35.9 dBi and 65.5%, respectively, could be achieved at the center frequency (9.65 GHz).
11:50 Shaping of Antenna Reflectors of Flexible Geometries
Leri Datashvili (Large Space Structures (LSS) GmbH, Germany)
Space telecommunication antenna applications with required in-orbit shape variation ask for morphing skins of antenna reflectors for fulfilment of diverse requirements. Mechanically reconf