Recent Articles
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Dual Function Metasurface: mm-Wave Radiator and Gain Enhancement Surface for Antenna-on-Chip
04 March 2026 Zere Iman, Yiyang Yu, Heng Wang, Muhammad Ikram and Atif Shamim investigate the use of Artificial Magnetic Conductors (AMCs) to improve the performance of Antenna-on-Chip (AoC) technology, which is becoming more relevant than ever with the advent of 6G. Due to the lossy nature of silicon (Si) in standard chip fabrication processes, AoCs suffer from poor gain and radiation efficiency. An elegant solution is to incorporate an Artificial Magnetic Conductor (AMC) structure beneath the AoC to isolate the Si substrate. This solution works well for mm-wave frequencies; however, the AMC is typically a large structure compared with the AoC and is generally limited to the single function of isolating the Si substrate. This work explores the potential of employing the AMC as a metasurface (MTS) antenna within the framework of AoC systems. The key focus of this work is to design a dual-functional MTS, which works as an AMC to enhance the gain and radiation efficiency of an AoC at one frequency, and as an independent radiator at another frequency.
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Wideband Low RCS Circularly Polarized Antenna Array Based on Hybrid Absorptive Frequency Selective Structure
25 February 2026 Bingyan Zhou, Di Gao, Binchao Zhang, Tian Lou and Cheng Jin propose a wideband low radar cross section (RCS) circularly polarized antenna array based on a hybrid absorptive frequency selective structure. To achieve wideband RCS reduction, a two-dimensional absorber and a three-dimensional absorptive frequency selective transmission (AFST) structure are successively integrated above the antenna. Furthermore, the transmission window of the AFST aligns with the operating band of the antenna to ensure its radiation performance. Specifically, the absorber consists of two perpendicular bent metal strips with central loading resistors, AFST is realized by adding a split-ring resonator in the center of the metal strip with resistors, and the circularly polarized antenna includes cutting radiation and parasitic patches.
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Single-and Dual-Band RF-Quasi-Reflectionless Planar Monopole Antennas and Their Application to Low-Reflection Antenna Arrays
23 February 2026 Runze Li, Li Yang, Zekai Luo, Xiu Yin Zhang and Roberto Gómez-García report an innovative family of planar monopole radiators with single- and dual-band operational characteristics and RF-quasi-reflectionless functionality. For the single-band case, it consists of a basic reflective-type planar monopole antenna that is loaded at its input terminal by an RF-absorptive branch composed of the in-series connection of a resistor and a short-ended stub. The stopband/non-radiated RF-input-signal power is consumed by the resistor of this lossy branch instead of being reflected back at the input port. This allows a simple but effective RF-isolator/attenuator-less protection of preceding RF active stages—e.g., RF amplifiers and mixers—from such unwanted RF-power echoes that may deteriorate their operation. For the dual-band counterpart, the reflective-type planar monopole radiator is modified with an etched radial slot to perform dual-frequency radiation.
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Multipath Measurement Leveraging In Situ Harmonic Transponders
23 February 2026 Jeff Frolik presents an alternative approach for wireless communication channel sounding in complex and cluttered environments, where communication is prone to multipath fading effects. Channel sounding is a measurement technique used to obtain data that characterize the extent of such fading. Conventional channel sounding nominally requires a transmitter at one end of the communication link and receiving equipment at the other end, making the measurement and characterization of cluttered, compact, and/or hazardous environments challenging. In this work, the author presents an alternative in which a harmonic transponder is embedded in the environment to be characterized, that is, at one end of the communication link. A transceiving interrogator is then located at the other end of the link. Harmonic transponders are small, passive, and nonlinear wireless devices that nominally receive an interrogation signal at one frequency ( f ) and backscatter harmonics (typically, 2f is of interest).
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Counting Human Targets in Distributed Antenna Systems via the Coherent Point Spread Function of Radio-Field Scattering Modes
20 February 2026 Frank E. Ebong and Andrea M. Tonello investigate the possibility to count the number of persons in an indoor environment using a distributed antenna system. While previous work has approached this problem empirically using machine-learning classifiers, they develop a physics-informed approach that leverages electromagnetic field perturbations captured by the scattering parameters (S-Parameters). Specifically, they present a method for counting multiple walking human targets in an indoor environment by analyzing the peak response of the Coherent Point Spread Function (CPSF) associated with orthogonal scattering modes of the radio field. They show that the maximum number of human targets that can be reliably counted is determined by the rank of the system, which is imposed by the number of distributed antennas.
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A Cost-Effective Liquid-Reconfigurable Reflective Metasurface With an Extended Beam-Scanning Range and a Wide 3-dB Gain Bandwidth Across All Scan Angles
19 February 2026 Liang-Yu Ou Yang and Siang-Cyun Liao present a cost-effective reconfigurable reflective metasurface composed of a saturated aqueous sodium chloride (NaCl) solution, enabling wide-angle beam scanning. The complex dielectric constant of the saturated NaCl solution was measured versus frequency, identifying the 0.4–1.6 GHz band over which the liquid can be approximated as a good conductor. Reflection-coefficient magnitude and phase were characterized versus liquid height. Two liquid heights, 5 mm and 82 mm, were selected as two element states with a 180° reflection-phase difference at 1 GHz and encoded as “0” and “1”, respectively, in a 1-bit scheme. The metasurface comprises a 10×10 array of elements, and the resulting 10×10 binary pattern formed by the 0/1 codes of all the elements is referred to as a configuration.
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Compact Dual-Mode CP Antenna With Wide AR Beamwidths for BDS-Based Vehicular Applications
13 February 2026 Zhuolin Deng, Jianbin Li, Huanhuan Peng, Qi Zou , Pei Xiao and Gaosheng Li present a low-profile single-feed CP antenna that realizes dual-band CP through a frequency-driven dual-mode mechanism with structural reuse. The antenna comprises a microstrip feed, a shared cross-slot aperture, an air gap, and a suspended radiating patch. At 1176.45 MHz, the cross-slot operates as a pair of orthogonal magnetic-dipole radiators to generate right-hand circular polarization (RHCP). At 1575.42 MHz, the same cross-slot transitions to a coupling aperture that excites the suspended patch, forming a CP patch-dominant mode. This shared-aperture modal reconfiguration integrates two distinct CP mechanisms within a compact structure.
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An RF-Switch-Enabled Low-Power Dual-Mode Reconfigurable Reflective Surface
12 February 2026 Hang Yu, Edward A. Ball, Rola Saad present a novel reconfigurable reflective surface capable of selective magnitude control at sub-6 GHz frequencies. Each unit cell integrates a low-power single-pole double-throw (SPDT) RF switch beneath the ground plane, providing two distinct impedance states that govern the reflection coefficient of the unit cell. The proposed configuration enables dynamic switching between reflective and absorptive modes at 5.50 GHz. A full system prototype comprising an 8×8 unit cells was fabricated and tested, the measured results exhibit good agreement with full-wave simulations, with the 1-bit (0°-180°) reflection phase control at 5.05 GHz and reflection magnitude switching between −2.4 dB and −26 dB at 5.50 GHz under TE-polarized excitation.
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Densely Coupled, Super-Realized Gain Printed Dipole Array With Defected Ground Structures
11 February 2026 Ihsan Kanbaz, Okan Yurduseven and Michail Matthaiou underscore the critical necessity of striking a delicate balance between directivity and impedance mismatch efficiency in Super-directive antenna arrays (SDAAs) to maintain high realized gain achieved by multi-parameter optimization. In this context, a four-element thin-wire dipole array is initially optimized using a multi-parameter differential evolution (DE) algorithm. After successfully applying this optimization via full-wave electromagnetic analysis software, we design and analyze printed versions of the optimized array. After attaining the targeted realized gain, the antenna undergoes bandwidth and sensitivity analysis, leading to fabrication and experimental verification.
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Design, Modeling, and Characterization of a Cascaded-Lens Antenna for 220–330 GHz With 51.1 dBi Gain
09 February 2026 Joel Dittmer, Akanksha Bhutani, Felix Beuthan, Jonas Krimmer, Thomas Zwick, Christian Koos and Sebastian Randel present a novel sub-THz high-gain cascaded-lens antenna design approach that employs Gaussian beam propagation combined with low-cost dielectric materials and standard manufacturing techniques. The proposed lens antenna, solely designed based on a Gaussian beam model, achieves a maximum measured peak gain of 51.1 dBi across a broad sub-THz frequency range from 220 to 330 GHz, demonstrated for the first time, to the best of the authors’ knowledge. The antenna comprises a WR3.4 diagonal horn as the primary radiator and a cascaded pair of dielectric lenses, comprising a double-concave lens followed by a double-convex lens. This cascaded configuration effectively controls beam divergence, increases the effective aperture, and enables higher gain with a more compact horn-to-lens spacing than conventional single-lens designs.
