Additional Articles
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Impact of 3-D Antenna Radiation Pattern in UAV Air-to-Ground Path Loss Modeling and RSRP-Based Localization in Rural Area
05 October 2023 Sung Joon Maeng, Hyeokjun Kwon, Ozgur Ozdemir and İsmail Güvenç investigate the impact of 3D antenna patterns on a UAV air-to-ground path loss model, utilizing datasets obtained from a measurement campaign. They conducted UAV experiments in a rural area at various fixed heights, while also characterizing the 3D antenna radiation pattern by using an anechoic chamber facility. By analyzing reference signal received power (RSRP) using path loss models that account for antenna patterns, the team observed that the measurement results, obtained at different UAV heights, aligned well with the two-ray path loss model when incorporating the measured antenna pattern.
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Low Sidelobe Pattern Synthesis of Array Antennas With a Triangular or Skew Lattice Using the IFT Method
05 October 2023 Will P. M. N. Keizer describes how the present 2D FFTs, direct and inverse, only applicable for rectangular lattices, can be modified in a simple way to make them suitable for the processing signals arranged along a triangular or skew grid. These two modified FFTs are subsequently implemented in the IFT method. The IFT method, updated in this way, is then very suited for the low sidelobe pattern synthesis of array antennas with a triangular lattice or skew lattice.
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A Global Optimization Method for Wideband and Small Supergain Arrays Design Using Artificial Neural Network
04 October 2023 Abdellah Touhami, Sylvain Collardey and Ala Sharaiha introduce an efficient approach for compact, wideband and supergain arrays design using artificial neural network (ANN) based optimization. The proposed method optimize at the same time the distance inter-elements of the array antenna, its input impedance as well as its directivity. Such global optimization considerably improves the performances of superdirective arrays in terms of gain, bandwidth and efficiency. The proposed method is used afterwards to synthesize a three-elements array using two different unit elements.
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Compact and Broadband Substrate Integrated Dielectric Resonator Antenna Suitable for 5G Millimeter-Wave Communications
27 September 2023 Jie-Er Zhang, Qinfang Zhang, Wei Qin, Wen-Wen Yang and Jian-Xin Chen propose a compact and broadband substrate-integrated dielectric resonator antenna (SIDRA) suitable for 5G millimeter-wave band applications. Four operating modes from three resonators, including TE111 and TE131 modes from the DR, slot mode from the H-shaped feeding slot, and patch mode from the inserted ring patch, are excited to achieve a bandwidth of 61.9% (24-45.5 GHz) with a compact size of 0.37λ0×0.37λ0×0.125λ0.
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Excitation Diversity in Adaptively Thinned Arrays for Microwave Sensing Applications
26 September 2023 Sandra Costanzo and Giovanni Buonanno propose an excitation diversity technique included in thinned arrays design to overcome the unacceptable discrepancy between the actual radiation pattern and the desired one, especially for small to medium-sized arrays, after reducing the complexity of the feeding network. Data distributions achieved with the above approach are averaged to obtain potential high-quality final images. Moreover, the proposed methodology can be easily implemented in real-time adaptive arrays.
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Design of Compact and High Isolation Dual-Polarized Antenna Array via Plasmonic Meta-Structure
20 September 2023 Zhang Wen Cheng, Shimeng Wang, Yue Teng Chen, Ji Ran Chen, Jing Cheng Liang, Feng Gao, Shuai Luan, Xin Liu, Hui Feng Ma and Tie Jun Cui propose a compact and high isolation dual-polarized antenna array based on plasmonic meta-structure operating at 2.58 GHz. The compact principle of the dual-polarized antenna is mainly based on spoof surface plasmon polariton (SSPP) radiation patch to support SSPP modes, which is fed by spatially coupled excitation. The cross-polarization coupling between two polarization ports can be improved to below −32 dB, showing high isolation characteristics.
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A Quad-Polarization and Beam Agile Array Antenna Using Rat-Race Coupler and Switched-Line Phase Shifter
18 September 2023 Maodudul Hasan, Eisuke Nishiyama and Ichihiko Toyoda propose a quad-polarized microstrip array antenna with beam steering capability. The proposed antenna consists of two patch elements, one rat-race coupler, and two 90° switchable phase shifters. With the aid of just four PIN diodes, the two 90° phase shifters can provide four different diode arrangements for each port of the rat-race coupler. The array elements are excited by using orthogonal feed lines. Due to the combination of the rat-race coupler and phase shifters, different phase conditions are generated between the patch elements or orthogonal modes of the patches.
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A Multi-Port Pattern Diversity Antenna With High Isolation
18 September 2023 Nghia Nguyen-Trong and Christophe Fumeaux propose a pattern-diversity antenna with 7 ports for multiple-input multiple-output (MIMO) applications. Orthogonal modes are utilized to achieve high isolation among all 7 ports in a relatively compact shared volume. As distinguishing feature from previous works, the concept of tripolarization is generalized, allowing to design antennas with a large number of orthogonal patterns in a single multi-port device.
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Ultra-Wideband Tightly Coupled Dipole Array Fed by a Tapering Meandered Balun
15 September 2023 Matthew W. Nichols, Michail O. Anastasiadis, Malcolm E. Taaffe, Elias A. Alwan and John L. Volakis present an ultra-wideband (UWB) phased array operating from UHF to C-bands (0.14 to 5.85 GHz). This design employs an integrated, compact tapered spline balun in conjunction with a triple-layer semi-resistive frequency selective surface (FSS) network. Notably, the integration of the meandered balun within a dual-polarized tightly-coupled dipole array (TCDA) allowed for a contiguous bandwidth of 40:1 with VSWR < 2.5 at broadside.
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Broadband Multi-Shaped Metasurface Circularly Polarized Antenna With Suppressed Non-CP Radiation Modes
13 September 2023 Nathapat Supreeyatitikul, Titipong Lertwiriyaprapa, Nonchanutt Chudpooti, Monai Krairiksh and Chuwong Phongcharoenpanich propose a multi-shaped metasurface broadband circularly polarized (CP) patch antenna with parasitic elements for 5G new radio (NR) applications. The proposed metasurface CP patch antenna comprises triple-layered substrates without air gap. The upper layer sits with multi-shaped metasurface elements and parasitic patches. The middle layer consists of an L-shaped slot functioning as the ground plane, and the lower layer contains a microstrip and a fan-shaped stub functioning as the feed line. The proposed metasurface CP patch antenna with parasitic elements is evaluated using characteristic mode analysis (CMA).
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Synthesis of Symmetric, Two-Element Biomimetic Antenna Arrays Using Singular Value Decomposition
04 September 2023 Son Vu, Saeid Jamilan, Barry D. Van Veen, Hung Luyen and Nader Behdad present a method for determining the four-port S-matrix of the external coupling network (ECN) for symmetric, two-element biomimetic antenna arrays (BMAAs) by employing singular value decomposition (SVD). The presented approach greatly facilitates the synthesis procedure of symmetric, two-element BMAAs and allows all possible scattering matrices of a four-port network realizing the ECN to be easily determined.
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Efficient Optimization Design of Large Circular Phased Arrays With Low Sidelobes for Beam Scanning
04 September 2023 Yi-Xuan Zhang, Tian-Ye Gao, Li Zhang, Yong-Chang Jiao and Tao Ni propose an efficient optimization design method for large circular phased arrays with low sidelobes for beam scanning. Based on the differential evolution algorithm (DE), each layer’s radius and element number are optimized to obtain the required element arrangement. If the main beam scans from the Z-axis, it is difficult for designers to find the maximum sidelobe.
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Low-Cost Hybrid Implementation of an Efficient E-Band Array Based on Stepped and Ridged Slots
01 September 2023 Sherif R. Zahran, Emilio Arnieri, Stefano Moscato, Matteo Oldoni, Dario Tresoldi, Giandomenico Amendola and Luigi Boccia present an 8×8 waveguide antenna array composed of stepped and slotted radiators for E-band applications. The proposed array architecture, including the feeding network, can be realized through the integration of a single metallic block adhered with an additional top photo-etched sheet. This approach effectively reduces manufacturing complexity, resulting in a low-cost solution that can be easily fabricated using standard market-ready technologies.
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Multi-Mode Antennas for Ultra-Wide-Angle Scanning Millimeter-Wave Arrays
28 August 2023 Gabriele Federico, Zhe Song, Guilherme Theis, Diego Caratelli and A. Bart Smolders present a novel multi-mode millimeter-wave antenna array with enhanced scan range and reduced scan losses. The individual array element consists of a differentially fed microstrip patch on top of which a cylindrical dielectric resonator is integrated. The radiation pattern of the antenna element can be reconfigured by changing the phase offset between the feeding ports of the patch and the dielectric resonator to excite two distinct radiating modes.
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A Dual-Band Dual-Polarized Base Station Antenna Array With Isolation Enhancement
28 August 2023 Lei Ge, Yinhui Wang, Mingye Du, Weiyang Liu and Yue Zhao design a dual-band dual-polarized antenna with isolation enhancement. The proposed antenna operates in the frequency range of 3.4–3.6 GHz and 4.8-5 GHz, where the center frequency of the high band (HB) is 1.4 times that of the low band (LB). Two radiating patches are placed in different layers to create the two distinct resonances and the bottom patch which is shorted to the ground by four metal posts acts as the ground for the top patch antenna. A metal wall is introduced between LB feeding probes to enhance the polarization isolation to more than 25 dB. Complementary split-ring resonator (CSRR) structures are etched on the feedlines to improve the cross-band isolation to over 25 dB.
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Near-Field Calibration Methods for Integrated Analog Beamforming Arrays and Focal Plane Array Feeds
11 August 2023 Roel X. F. Budé, Kevin A. P. Van Hastenberg, Ulf Johannsen and A. Bart Smolders propose a near-field calibration method for millimeter-wave analog beamforming array antennas and focal plane array antennas. Nonidealities of the beamformer integrated circuits with vector modulators are taken into consideration, and a way to reduce the measurement set for vector modulators with high resolution is proposed. This method is both practical and achieves a good calibration as evidenced by measurements of the radiation patterns, and it is suitable for use in an automated factory calibration setup.
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Coupled Array of Diverse Elements for Wideband High Spherical Coverage
10 August 2023 Quangang Chen, Veli-Pekka Kutinlahti, Jaakko Haarla, Anu Lehtovuori and Ville Viikari propose a flexible cluster array concept utilizing diverse antenna elements and the mutual coupling among them to improve the spherical coverage. This innovative approach can not only enhance the impedance matching but also improve the beamforming performance across a wide frequency band by adjusting excitation amplitudes and phases. Equations are derived to achieve specific objectives such as minimizing the total active reflection coefficient or maximizing the realized gain of an antenna array.
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Analysis and Experimental Demonstration of Reflectarray Antennas in Quasi-Regular Lattices
09 August 2023 Borja Imaz-Lueje, Juan Córcoles, Marcos R. Pino and Manuel Arrebola present investigations on reflectarray antennas using non-periodic element distributions. The study involves the analysis and design of two reflectarrays based on quasi-periodic lattices with rectangular and pentagonal profiles, whose performance is compared with equivalent reflectarrays comprised of regular grids of elements. The characterization of these antennas is performed using a tailored analysis technique for reflectarrays with periodical and quasi-periodical grids. The proposed technique uses the Method of Moments under local periodicity conditions (MoM-LP) to compute the field on the surface of each cell and then the far field radiated by the aperture.
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Shared Impedance Noise Coupling in Radio Receivers
08 August 2023 Yihong Qi and Yunlong Luo elucidates a shared impedance noise coupling mechanism, which sheds light on how passive antennas can introduce excess noise into the wireless system. This article introduces the general theory of antenna noise temperature, providing an explanation for the mechanism of noise coupling through a shared impedance path. Additionally, a mathematical expression for radiated sensitivity is presented.
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Uncertainty Analysis Methodology for Measurements of Dynamic Millimeter-Wave Channels
01 August 2023 Robbert Schulpen, A. Bart Smolders, Ulf Johannsen, and L. A. Bronckers present a novel uncertainty analysis methodology to quantify uncertainties of condensed parameters in measurements of dynamic millimeter-wave channels. The bandwidth limitation and multipath threshold are identified as important impairments. Therefore, the methodology provides three uncertainty metrics for condensed parameters, namely a standard uncertainty to quantify the impact of random variations; a bias due to the multipath threshold; and a total bias including the impact of the bandwidth limitation.
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End-to-End Channel Modeling and Generation Software Based on Statistical mmWave Channel Model
28 July 2023 Yusuke Koda, Ruiting Ouyang and Hiroshi Harada develop an end-to-end software to automatically perform channel modeling and simulation with statistical validity just by inputting measured power profiles. The developed software involves comprehensive algorithms to reach channel parameter extraction, such as multi-path component (MPC) extraction, MPC clustering, and maximum-likelihood estimations for respective parameters. They highlight that channel parameters reported by the IEEE 802.15.3c task group (TG) do not necessarily fit the original power profiles, highlighting the need to examine the validity of the existing parameters by leveraging the developed software.
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Design of a Compact 4-Element GNSS Antenna Array With High Isolation Using a Defected Ground Structure (DGS) and a Microwave Absorber
25 July 2023 Abdullah Madni, and Wasif Tanveer Khan presents a compact (125 mm diameter) wideband 4-element antenna array with a high isolation level for global navigation satellite system (GNSS) applications. The array consists of four right hand circularly polarized (RHCP) single feed rectangular patch antennas that can cover BeiDou B1 band (1561.098 MHz), GPS L1 band (1575.42 MHz), Galileo E1 band (1575.42 MHz) and GLONASS G1 band (1602 MHz) of the GNSS upper L-band (1559 - 1610 MHz). The proposed array has a wide frequency bandwidth of 80 MHz with an axial ratio of less than 3 dB. The patch elements are designed on a substrate which has a high dielectric constant to achieve a compact size.
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A Study on mm-Wave Propagation in and Around Buildings
20 July 2023 Leonardo Possenti, Marina Barbiroli, Enrico M. Vitucci, Franco Fuschini, Mattia Fosci, and Vittorio Degli-Esposti analyze in depth the peculiar characteristics of mm-wave propagation, joint measurement and simulation campaigns in indoor and outdoor microcellular environments. The investigation highlights that the assumption that mm-wave NLoS connectivity is hardly feasible is not necessarily true as significant reflections, scattering and even transmission mechanisms can provide good NLoS coverage in the considered indoor and outdoor scenarios. This is also reflected in the limited angle-spread differences between LoS and NLoS locations in some cases.
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Dual-Port RHCP Compact Antenna at 868 MHz Using a 120° Hybrid Coupler
19 July 2023 Fabien Ferrero, and Le Huy Trinh present the design of a compact dual-port circularly polarized antenna based on the new coupler topology. The antenna can radiate a right-hand circular polarization (RHCP) in two opposite directions depending on the input port. In the proposed structure, the radiating system has three inverted F antennas connected to a 120° hybrid coupler. The modeling and design of the 5-ports hybrid coupler are described and experimentally validated.
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Compact U6G Massive MIMO Antenna Arrays With Double-Layer Partial Reflective Decoupling Layers for Mutual Coupling Suppression
18 July 2023 Ting Liu, Jiayue Jiang, Luyu Zhao, Ge Zhao, Huiqing Zhai, Yuan-Ming Cai, Teyan Chen, and Wenwei Xu utilize a systematic decoupling strategy of two partial reflective decoupling layers (PRDLs) and dummy decoupling probes (DDPs) to suppress the complicated couplings in a ±45° dual-polarized, compact antenna array operating at Upper 6 GHz (U6G, 6425–7125 MHz) bands. Finely engineered neutralization electromagnetic waves are introduced by two PRDLs to counteract the original couplings. Two layers of PRDLs are placed above the antenna array in a step-by-step manner to gradually cancel out several major couplings while DDPs are placed around the antenna elements to reduce the remaining couplings.
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Wide-Angle Beam Scanning Phased Array Antennas: A Review
18 July 2023 Ming Li, Shu-Lin Chen, Yanhui Liu, and Y. Jay Guo investigate and discuss several challenges that hinder wide-angle beam scanning (WABS) for conventional phased array antennas (PAAs), including the strong mutual coupling, narrow beamwidth of the element antenna, etc. in this review. They then review and summarize a variety of innovative techniques to overcome these challenges, and analyze potential research gaps of WABS PAAs for future emerging applications.
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Airborne Reflector-Based Ground Penetrating Radar for Environmental and Archaeological Studies
17 July 2023 Zayed Mohammad, and Andrew M. Chrysler design and propose a wideband airborne reflector-based ground penetrating radar (GPR). It consists of 15 discrete panels, each panel supported by a single multi-rotor unmanned aerial vehicle (UAV). A lightweight, wideband Vivaldi antenna was developed as the feed structure. The antenna operates within the frequency range of 100–500 MHz and has a bandwidth of 387 MHz. The proposed antenna will possess a penetration depth of 2 m.
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Feed Integration and Packaging of a Millimeter-Wave Antenna Array
17 July 2023 Matthew W. Nichols, Stavros Koulouridis, Satheesh B. Venkatakrishnan, Elias A. Alwan, and John L. Volakis present and demonstrat a novel approach for integrating a wideband vertically fed antenna array at Millimeter-Wave (mm-Wave) frequencies. Specifically, a novel cost-effective Antenna-In-Package (AiP) fabrication approach is presented, then a prototype operating from 55 GHz to 64 GHz is built while predicted performance is verified via measurements. This approach relies on separating fabrication into- the array and
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A 3-D Printed Ultra-Wideband Achromatic Metalens Antenna
17 July 2023 Yu-Xuan Xie, Geng-Bo Wu, Wen-Qiang Deng, Shu-Yan Zhu, and Chi Hou Chan propose a millimeter-wave achromatic metalens antenna using three-dimensional (3D) printing technology to reduce the dispersion effect and enlarge its bandwidth. The proposed ultra-wideband achromatic metalens antenna consists of a convex-liked metalens (VLM) and a concave-liked metalens (CLM) integrated as a metalens group.
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A Technique to Realize Aperture Coupled Microstrip Patch as a Truly Low Cross-Polar Antenna by Mitigating the Major Issues Over its Skewed Radiation Planes
14 July 2023 Sk Rafidul, Chandrakanta Kumar, and Debatosh Guha address and resolve the limitation of the low cross-polarized (XP) radiations of aperture-fed microstrip patch by introducing a pair of additional printed loops adjacent to the radiating patch.Detailed investigations leading to the design insight have been presented. A C-band rectangular patch promises as much as 7 dB suppression in the diagonal plane XP level keeping the overall performance across the principal radiation planes unchanged.
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Antenna Design for the Arctic Weather Satellite Microwave Sounder
14 July 2023 Roland Albers, Anders Emrich, and Axel Murk propose an antenna design for the Arctic Weather Satellite (AWS), a prototype mission for an operational constellation of microwave sounders, complimenting existing meteorological sounders. The AWS is a microsatellite with a single cross-track scanning radiometer operating in the 54, 89, 183 and 325 GHz bands. Due to the small platform size, the core design focus of the radiometer’s quasi-optics is less complexity and a more compact setup than comparable spaceborne microwave sounders. The main challenge for instrument performance is that only one of the four horns can be located in the focus of the scanning reflector. Consequently, scan angle dependent spillover variations and beam asymmetries can occur. This paper details the simulation and optimisation efforts of the quasi-optics to minimise the aforementioned effects.
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Tuning the Angular Characteristics of Biomimetic Antenna Arrays
11 July 2023 Ines Dorsch Dominik Schwarz, Sarah Forster, and Christian Waldschmidt present the concept and the design process of a tunable Biomimetic Antenna Arrays (BMAA). By electronically tuning varactor diodes, such an array can adapt its angular characteristics depending on the direction-of-arrival (DoA) and signal strength of a radar target. The theoretical requirements for the desired task are examined with general S-parameter simulations. Extensive circuit simulations of a proposed architecture unveil a variety of achievable designs of tunable BMAAs. Radar measurements of different implementations in the 77 GHz range and the theoretical analysis are in good agreement.
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Receive Mode Time-Modulated Antenna Array Incorporating Subsampling—Theoretical Concept and Laboratory Investigation
07 July 2023 Edward A. Ball, Sumin David Joseph and Alan Tennant present an eight element Subsampling Time Modulated Array (STMA) operating in receive mode with a carrier at 2.4 GHz using bespoke Radio Frequency (RF) hardware. Each STMA cell incorporates subsampling functionality, with the sampling frequency significantly below the carrier frequency and requiring minimal additional hardware. By using this concept, the hardware required for a receiver incorporating an antenna array can be reduced and costs saved. STMA design equations and architecture strategies are presented, and a prototype hardware demonstrator is introduced.
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A Dual Wide-Band Mushroom-Shaped Dielectric Antenna for 5G Sub-6-GHz and mm-Wave Bands
05 July 2023 Reza Shamsaee Malfajani, Hamed Niknam, Sampada Bodkhe, Daniel Therriault, Jean-Jacques Laurin and Mohammad S. Sharawi present the design and implementation of a dual wide-band mushroom-shaped antenna. The antenna consists of a cylindrical dielectric resonator (cDRA), a cylindrical dielectric rod as a waveguide (cDR), and a dielectric lens (DL). The cDRA in conjunction with the DL acts as a sub-6-GHz antenna. At the mm-wave band, the small cDR acts as a waveguide, which transfers the wave from the feed toward the larger cDRA and the DL in order to produce a high gain.
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A Diffusion Model for Multi-Layered Metasurface Unit Cell Synthesis
04 July 2023 Chen Niu, Mario Phaneuf, and Puyan Mojabi propose a deep learning approach based on a diffusion model to yield metasurface unit cell designs. This method takes desired two-port scattering parameters along with the frequency of operation in an attempt to synthesize three-layered metasurface unit cells. The core of this approach lies in casting the three-layered unit cell synthesis process as conditional three-channel binary image synthesis. The conditions are governed by the desired scattering parameters at a given frequency whereas the binary nature implies the presence and absence of metallic traces.
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A Deep Learning-Based Approach to Design Metasurfaces From Desired Far-Field Specifications
04 July 2023 Chen Niu, Mario Phaneuf, Tianke Qiu and Puyan Mojabi develop a deep learning neural network model in conjunction with a method to incorporate auxiliary surface waves for the macroscopic design of transmitting metasurfaces. The main input to the neural network model is the user-defined desired far-field specifications. This network is used to calculate the required tangential electromagnetic fields on the metasurface. These fields will then be augmented by incorporating auxiliary surface waves along the metasurface for power redistribution to satisfy the requirement for having lossless and passive metasurfaces.
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Statistical Evaluation of the Role of GNSS Signal Propagation Orientation in Low-Latitude Amplitude Scintillation Severity
30 June 2023 Alison Moraes, Jonas Sousasantos, Bruno J. Affonso, Paulo R. P. Silva, Eurico R. De Paula and João F. G. Monico perform an analysis considering aspects of the orientation of the propagation of the radio signals through the plasma bubbles structures to evaluate how this geometry can affect the scintillation profile. The dataset covers five months of records from three stations over the Brazilian region during the last solar cycle maximum. The initial results indicate that propagation paths fully aligned are consistently related to larger values of S4 and more severe scintillation.
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Physics-Based Coherent Modeling of Long-Range Millimeter-Wave Propagation and Scattering in Rain
12 June 2023 Behzad Yektakhah and Kamal Sarabandi present a fast and accurate numerical method for phase coherent modeling of wave propagation and scattering in random media, like rain. In this approach, the random medium is divided into sufficiently large finite slabs and each slab is modeled as a network with multiple input/output ports where ports represent rays with different polarizations propagating in different directions entering and leaving the slabs. The proposed method considers multiple scattering among all scatterers and thus the entire physics of wave-particle interactions is accounted for.
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Bandwidth Enhancement of Low-Profile Metasurface Antenna Using Nonuniform Geometries
08 June 2023 Hayden A. Banting and Carlos E. Saavedra investigate artificial magnetic conductor metasurface antennas using a robust, surrogate-assisted, differential evolution optimization technique. Using a uniform metasurface array configuration as a starting point, multiple array configurations are parameterized and the differential evolution optimizer yields nonuniform array geometries exhibiting wideband performance. Two prototypes are fabricated and characterized to experimentally confirm the advantages of proposed designs.
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Post-Fabrication Technique to Manage Material Variations in 3-D Printed Microstrip Antenna Substrates
08 June 2023 Zere Iman, Zubair Akhter, Yiyang Yu and Atif Shamim present a post-fabrication technique capable of compensating for variations in the εr of 3D printed substrates, focusing on microstrip patch antennas (MPAs). The proposed technique, suitable for correcting the fr of a single microstrip patch antenna, uses either a single blind via or an array of vias in the 3D-printed substrate. Two MPAs were fabricated on a 3D-printed substrate and it is shown that their fr values can be shifted upward or downward by following the proposed guidelines.
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3D Printed Hemispherically Radiating Antenna for Broadband Millimeter Wave Applications
23 May 2023 Lukas Engel, Danti Khouri, Konstantin Lomakin, Andreas Hofmann, Micha Kleinlein, Ingrid Ullmann, Martin Vossiek, and Gerald Gold present a 3D printed monolithic antenna for millimeter wave-sensing applications with a full hemispherical coverage. The antenna is designed as an ensemble of a waveguide horn antenna and a differentially fed dipole antenna. The slotted waveguide approach was utilized to improve the manufacturing quality on the waveguide inside.
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Reflectarray Feeds Augmented With Size-Reducing GRIN Lenses for Improved Power Handling and Aperture Efficiency
19 May 2023 Eric B. Whiting, Galestan Mackertich-Sengerdy, Ryan J. Chaky, Colin A. Mussman, Sawyer D. Campbell, Pingjuan L. Werner, and Douglas H. Werner demonstrate highly effective approaches for optimizing GRIN lenses to achieve different design objectives including high gain radiation with a compact feed as well as improved aperture efficiency and power handling. Additive manufacturing is employed to fabricate the lenses, and measured results agree well with simulations.
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Analytic Approximation of In-Body Path Loss for Implanted Antennas
15 May 2023 Mingxiang Gao, Zvonimir Sipus, and Anja K. Skrivervik present a simplified model of an implanted antenna that provides closed-form approximate expressions to estimate EM radiation from the implant. In particular, they extend the expressions for the reactive near-field losses to both deep and shallow implants, by taking into account the implantation depth.n The proposed approximate method is verified by comparing the results obtained with the full-wave simulations in the case of a miniature implanted antenna, and with both simulated and measured results from two practical examples found in the literature.
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3-D Printable Synthetic Metasurface to Realize 2-D Beam-Steering Antenna
10 May 2023 Foez Ahmed, Touseef Hayat, Muhammad U. Afzal, Shiyu Zhang, Karu P. Esselle, and William G. Whittow present highly radio-frequency (RF) transparent phase gradient synthetic metasurfaces made of sub-wavelength-sized 3D printable meta-atoms with tailored permittivity that cannot be achieved with off-the-shelf, commercially available materials. The synthesized meta-atoms design uses one dielectric block of PREPERM ® ABS 1000 material with air and metallic inclusions to make low- and high-permittivity materials. The inclusions’ size and height are varied to achieve a complete phase range from 0 to 360°, while maintaining transmission magnitudes greater than −3.0 dB.
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A 3D-Printed Encapsulated Dual Wide-Band Dielectric Resonator Antenna With Beam Switching Capability
09 May 2023 Reza Shamsaee Malfajani, Hamed Niknam, Sampada Bodkhe, Daniel Therriault, Jean-Jacques Laurin, and Mohammad S. Sharawi present the concept of encapsulated dielectric resonator antennas (E-DRAs). In E-DRAs, smaller-sized DRAs with a specific permittivity is embedded inside a larger DRA with a lower permittivity allowing for simultaneous efficient radiation at two widely separated and widely covered frequency bands. The proposed E-DRAs cover both the sub-6-GHz band (with a large size DRA) and mm-wave band (with smaller sized DRAs) for 5G and beyond applications.
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3-D Printed All-Dielectric GRIN Lens Antenna With an Integrated Feeder
05 May 2023 Anastasios Paraskevopoulos, Francesca Maggiorelli, Ilir Gas Hi, Cristian Della Giovampaola, Matteo Albani, Stefano Maci present the design, fabrication, and experimental verification of a new type of Graded-index (GRIN) lens antenna with an integrated feeder. The continuously varying refractive index distribution is chosen appropriately to offer the rays collimation at the lens aperture. It is practically implemented by varying the material density in a host medium, thus realizing a new type of all-dielectric high gain antenna, entirely using 3D printing. This solution can find application to high gain wireless communication and measurement systems.
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Planar Array Subarray Division Method in Microwave Wireless Power Transmission Based on PSO&K-Means Algorithm
27 April 2023 Qian He Zhang and Zhao Yang Shen propose a clustering algorithm based on a combination of the particle swarm algorithm and the K-means algorithm for the subarray partitioning of planar arrays to address the problem of maximizing beam collection efficiency in microwave wireless power transmission. The effectiveness of the proposed method is evaluated by integrating the beam collection efficiency with parameters such as the receiving area and the size of the planar array.
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Fully Printed 3-D Antennas With Wideband Radiation Isotropy Based on Annular Currents Models
02 May 2023 Ruiqi Wang, Kirill Klionovski and Atif Shamim propose a theoretical model based on annular ring currents to synthesize quasi-isotropic antenna radiation patterns. The theoretical model shows that wideband radiation isotropy can be achieved by optimizing the combination of azimuthal currents. We subsequently present spherical and cubical ESA designs that achieve measured wide impedance and radiation isotropy bandwidths exceeding 10% for the GSM900 band.
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Circularly-Polarized Patch Antennas With Enhanced Bandwidth Based on Capacitively Coupled Orthogonal Patch Radiators
02 May 2023 Qiong-Sen Wu, Xiao-Yu Tang, Xiao Zhang, Lei Zhu, Gary Zhang and Chun-Bing Guo propose circularly-polarized (CP) patch antennas with enhanced bandwidth based on capacitively coupled orthogonal patch radiators Several patch radiators are alternately arranged one by one along the x - and y -direction, producing orthogonal currents and far fields. The adjacent patch radiators are coupled to each other and the coupling structure not only contributes to power distribution but also introduces 90° phase shift for circularly-polarized radiation.
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A Concept of Advanced Design Governed by Theoretically Predicted Current Distributions on the Ground Plane Beneath an Aperture-Fed Microstrip Antenna
02 May 2023 Debi Dutta, Debatosh Guha and Chandrakanta Kumar explore a way of mitigating near field issues based on theoretical analysis and propose a simple strategic approach to reform the same for a rectangular patch. A representative design, theoretical justification, and experimental studies with an S-band prototype have been presented. XP suppression by 11dB has been experimentally achieved in the diagonal (D-) plane with no considerable changes in its H- or E-plane. That eventually attains an overall XP discrimination by nearly 27dB from the perspective of 3D radiation scenario.
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Uniform Analysis of Multipath Components From Various Scenarios With Time-Domain Channel Sounding at 300GHz
02 May 2023 Johannes M. Eckhardt, Alper Schultze, Ramez Askar, Tobias Doeker, Michael Peter, Wilhelm Keusgen, and Thomas Kürner present a uniform and collaborative data evaluation of measurement sets from two different time-domain channel sounders. The channels show a great variety of characteristics depending on the scenario, the line-of-sight condition and the signal-to-noise ratio requirements of the prospective communication system. The extracted multipath components are published as research data for future analytical studies and simulations in relevant scenarios for the sixth generation of mobile systems.
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Indirect Applications of Additive Manufacturing for Antennas
10 April 2023 Jonathan D. Lundquist, Lauren Linkous, Umar Hasni, and Erdem Topsakal report the fabrication methodology of stereolithography (SLA) printed molds for metal and resin cast antennas. In the first method, a conical horn created using metal cast molds printed from a glass-filled resin utilizes a casting technique allowing for low-cost 3D printing to fabricate metal antennas. The second casting method demonstrates the interchangeability between creating parts via SLA printing with a glass-filled resin and using the same resin cast into a reusable Polydimethylsiloxane (PDMS) mold.
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3-D-Printed Spiral Leaky Wave Antenna With Circular Polarization
05 April 2023 Tomás Lira-Valdés, Eva Rajo-Iglesias, and Francisco Pizarro present the design, manufacturing and measurement of a fully dielectric leaky wave antenna operating at 18 GHz. The antenna is composed of a grounded dielectric substrate with a top dielectric Archimedean spiral corrugation, which allows obtaining a directive pencil-beam in broadside direction with circular polarization depending on the turning sense of the spiral.
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Practical Correlation-Matrix Approaches for Standardized Testing of Wireless Devices in Reverberation Chambers
30 March 2023 Kate A. Remley, Sara Catteau, Ahmed Hussain, Carnot L. Nogueira, Mats Kristoffersen, John Kvarnstrand, Brett Horrocks, Jonas Fridén, Robert D. Horansky, and Dylan F. Williams extend the autocorrelation-based approaches currently used in standards to full correlation-matrix-based approaches in order to identify correlation between both spatially adjacent and non-adjacent samples in reverberation-chamber measurements. They employ a scalar metric that allows users to identify the number of effectively uncorrelated samples in new types of stirring sequences.
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3-D Printed Dually Symmetric Orthomode Transducer and Horn Antenna at X-Band
03 April 2023 Ian Goode, and Carlos E. Saavedra present a dually symmetric orthomode transducer (OMT) and horn antenna for both single port linearly polarized operation and dual port circular polarization use. The feed uses two waveguide splitters and a feed bend to feed a four-port horn antenna that has the two groups of ports orthogonal to each other to produce a symmetric radiation pattern. The feed is printed from 316L stainless steel while the horn is printed from a plastic polymer and metallized using aluminum tape.
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Systematic Design Method for Mutual Coupling Reduction in Closely Spaced Patch Antennas
28 March 2023 Hui Deng, Lei Zhu, and Zhao-An Ouyang present a systematic design approach to reduce the mutual coupling between a pair of closely spaced microstrip patch antennas (MPAs). This method can effectively overcome the main drawback of previous two-path cancellation methods, i.e., lack a systematic design guideline and heavily rely on the time-expensive trial-and-error procedure to mitigate mutual coupling in a best-effort manner. They propose the concept and workflow of the systematic design method, and introduce the circuit-level modeling upon the proposed two coupling routes.
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Angle-Dependent Synthesis Method for Holographic Multi-Feed Antennas
27 March 2023 Thomas Frey, Maximilian Döring, Nico Riese, Christian Waldschmidt, and Tobias Chaloun present a novel synthesis method for holographic multi-feed antennas to combine all sub-holograms into an angle-dependent shared holographic aperture. In order to find the global error minimum between the shared holographic aperture and all ideal sub-holograms, a non-pixel-based genetic optimization is used. For a more accurately implementation of the analytical impedance tensor an eigenvector approach taking all tensor components into account is introduced.
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Additive Manufacturing of Linear Continuous Permittivity Profiles and Their Application to Cylindrical Dielectric Resonator Antennas
16 March 2023 Simon P. Hehenberger, Stefano Caizzone, and Alexander G. Yarovoy consider the utilization of additive manufacturing (AM) to engineer the permittivity profile of dielectric resonator antennas (DRAs). The capabilities of AM are exploited to create continuously swept permittivity profiles and applied to cylindrical DRAs. The spatial variant lattices (SVL) synthesis algorithm is implemented to create the desired permittivity profiles from a single material, and resulting geometries are manufactured using a high-permittivity material in a fused deposition modeling AM process.
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Additively-Manufactured All-Dielectric Microwave Polarization Converters Using Ceramic Stereolithography
15 March 2023 Steve M. Young, Mark Kauf, Jeffrey Kutsch, and Anthony Grbic report a class of all-dielectric, additively-manufactured polarization converters with tailored temporal frequency responses within the Ku and Ka microwave bands (15– 40 GHz). These multi-layer devices consist of cascaded, subwavelength, high-contrast gratings with different fill fractions and orientations, providing control over the effective anisotropic properties of each layer. Three example devices based on alumina/air gratings have been monolithically fabricated using ceramic stereolithography: a broadband reflective half-wave plate, a broadband isotropic polarization rotator, and a dual-band linear-to-circular polarization converter.
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Highly Efficient Calibration of Antenna Arrays by Active Targets in the Near-Field
08 March 2023 Matthias Linder, Benedikt Meinecke, Enes Halici, Dominik Schwarz, and Christian Waldschmidt propose a calibration setup employing active calibration targets (ACT) to reduce the calibration effort, hereby defined as the number of required measurements. The setup allows the storage of a multitude of data points within a single measurement. It is placed in the near-field of the array to relax the requirements on the size of the anechoic chamber. Employing multiple targets makes it challenging to compensate for the near-field effects.