IEEE Open Journal of Antennas and Propagation最新文献

{"title":"An RF-Switch-Enabled Low-Power Dual-Mode Reconfigurable Reflective Surface","authors":"Hang Yu;Edward A. Ball;Rola Saad","doi":"10.1109/OJAP.2026.3664172","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3664172","url":null,"abstract":"This paper presents 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 <inline-formula> <tex-math>$8times 8$ </tex-math></inline-formula> 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. In addition, various geometric coding patterns were explored and implemented to further assess the surface’s capability for a thinned reconfigurability and improved power efficiency. Three sets of ring-based surface configurations were investigated in detail, demonstrating that the surface is capable of selective magnitude control at both 5.05 GHz and 5.50 GHz under these pattern configurations. Specifically, these configurations enable quantized reflection magnitude control at 5.05 GHz, with an average step size of circa 5 dB. The results confirm the surface’s flexible reconfigurability and reveal that activating only 75% of the available switches achieves performance comparable to full-surface operation, effectively reducing control complexity and overall power consumption.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"823-837"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11395260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148517113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Short-Range mmW In-Band Full-Duplex Channels With a Focus on Antenna Characteristics","authors":"Yagmur Ozturk;Niru K. Nahar;Kubilay Sertel","doi":"10.1109/OJAP.2025.3637086","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3637086","url":null,"abstract":"We demonstrate a systematic over-the-air (OTA) characterization approach for short-range, high-data rate mmW in-band full-duplex (IBFD) channels and investigate the impact of the radiation characteristics and relative positioning of the mmW antennas on the channel response. An automated setup is developed for the characterization of two representative short-range IBFD channels formed by two different types of antennas, namely the endfire mode Yagi-Uda and broadside mode Tightly Coupled Dipole Array (TCDA) antennas operating at 57-64 GHz band. An extensive set of channel data with various antenna configurations are measured and tabulated in form of heatmaps for visual presentation of channel strength. Measured port S-parameters of the Tx-Rx antenna pairs, transmission levels, RMS delay spread and self-interference levels of the short-range system are analyzed. We report the key characteristics of short-range channels formed by representative endfire and broadside antennas to demonstrate the antenna selection process for short-range communication channels with various physical requirements and configurations. Short-range mmW channels allow for high-data-rate communications without needing a physical connection, and therefore, they can possibly replace mechanical connections, such as USB ports. However, estimation of such channels can be challenging as strong interactions between the transmitting and receiving antennas can arise in short-range channels, distorting channel waveforms and increasing the bit error rates (BER).","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"1078-1090"},"PeriodicalIF":3.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11269019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148214878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maximum Coupling Channels Between Multimodal Aperture Antennas With Simultaneous Hermitian Matching","authors":"Coady K. Lewis;Faris Alsolamy;Anthony Grbic","doi":"10.1109/OJAP.2025.3627890","DOIUrl":"https://doi.org/10.1109/OJAP.2025.3627890","url":null,"abstract":"Subwavelength control of field profiles with metasurfaces has redefined antenna design, making optimal apertures attainable. In this work, a design framework is outlined for achieving maximum coupling of power between two arbitrary aperture antennas, by means of multimodal network theory. First, the interaction of the apertures is characterized with a multimodal two-port impedance matrix. From here, the design procedure is a two-step process: multimodal impedance matching, followed by solving for optimal weights of the transmit aperture modes. Specifically, the concept of simultaneous conjugate matching is extended to multimodal systems. By applying the well-known fixed-point iteration algorithm, we find the termination impedance matrices that achieve a simultaneous Hermitian impedance match at both aperture ports. Subsequently, a coupling coefficient eigenproblem is solved to find optimal modal current excitation vectors on the transmit aperture. Each of these modal current vectors, when applied to the transmit aperture, excites an independent eigenchannel of the aperture pair. To demonstrate the proposed theory, simulations of multimodal aperture designs are reported, demonstrating maximum coupling with multiple eigenchannels. The theoretical aperture coupling approach presented in this work is immediately applicable to metasurface antenna design for radiative wireless power transfer systems. The approach also has broad applications in near-field communication and sensing, and the concept of multimodal impedance matching with fixed-point iteration is fundamentally general, applicable to any linear multimodal two-port device.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"1033-1049"},"PeriodicalIF":3.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11223077","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148214891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Densely Coupled, Super-Realized Gain Printed Dipole Array With Defected Ground Structures","authors":"Ihsan Kanbaz;Okan Yurduseven;Michail Matthaiou","doi":"10.1109/OJAP.2026.3663868","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3663868","url":null,"abstract":"Super-directive antenna arrays (SDAAs), conventionally designed to achieve exceptional directivity through mutual coupling, face an inherent drawback regarding their high impedance mismatch. Despite their high directivity, the considerable decline in the mismatch efficiency, which is more pronounced for a higher number of elements, has historically undermined the practical applications of such arrays. To address this limitation, our study underscores the critical necessity of striking a delicate balance between directivity and impedance mismatch efficiency in 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. Consequently, both simulation and experimental results are closely matched; thus, a compact wideband printed dipole antenna array with a realized gain value of 9.5 dBi, accompanied by an exceptionally high total efficiency as 85.3%, is introduced to the literature for dense array applications, such as massive multiple-input multiple-output (MIMO), significantly enhancing the performance and feasibility of future wireless communication technologies.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"808-822"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11393544","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148513602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual Function Metasurface: mm-Wave Radiator and Gain Enhancement Surface for Antenna-on-Chip","authors":"Zere Iman;Yiyang Yu;Heng Wang;Muhammad Ikram;Atif Shamim","doi":"10.1109/OJAP.2026.3670685","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3670685","url":null,"abstract":"With the advent of 6G, Antenna-on-Chip (AoC) is becoming more relevant than ever. However, due to the lossy nature of silicon (Si) in standard chip fabrication processes, these antennas suffer from poor gains and radiation efficiencies. 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, as compared to the AoC, and is limited to a single function of isolating the Si substrate. Enhancing the functionality of the AMC can optimize the performance of such compact designs, where efficient use of space as well as integration of multiple functionalities is of paramount importance. Therefore, 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. As a proof of concept, we have shown that an on-chip monopole antenna’s gain and radiation efficiency is enhanced by 5.5 dBi and 20% respectively at 79 GHz through an integrated AMC structure. It is shown that this AMC can be optimized to radiate as an independent MTS antenna through Characteristic Mode Analysis (CMA) with a variety of radiation patterns for various modes. The fabricated prototype demonstrates one of these modes, where the MTS antenna shows a measured peak gain of 4.0 dBi at 94 GHz with a broad boresight radiation pattern.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"908-917"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11421344","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148514229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Cost-Effective Liquid-Reconfigurable Reflective Metasurface With an Extended Beam-Scanning Range and a Wide 3-dB Gain Bandwidth Across All Scan Angles","authors":"Liang-Yu Ou Yang;Siang-Cyun Liao","doi":"10.1109/OJAP.2026.3666424","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3666424","url":null,"abstract":"This paper presents 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 <inline-formula> <tex-math>$10times 10$ </tex-math></inline-formula> array of elements, and the resulting <inline-formula> <tex-math>$10times 10$ </tex-math></inline-formula> binary pattern formed by the 0/1 codes of all the elements is referred to as a configuration. Ten thousand configurations were generated and simulated under horn illumination to obtain far-field patterns, which were used to train a convolutional neural network (CNN) model developed in this work. The trained CNN was then used to synthesize target patterns. Simulated and measured patterns and directional gain bandwidths agree well, demonstrating a measured beam-scanning range up to ±75°. Across these scan angles, the measured main-beam gain variation remains below 2.7 dB, whereas the simulated variation remains below 2.4 dB, and the measured 3-dB gain bandwidth exceeds 20% for all scan angles. Mechanism analysis shows that a nearly omnidirectional element pattern and weak inter-element mutual coupling help maintain stable directional gain at large scan angles, indicating the proposed metasurface is promising for communication and radar applications.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"849-860"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11400672","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148515318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical Polarized Helicoid Array With Full Azimuth Beam-Scanning","authors":"Yat Hin Chan;Hossein Mardani;Neil Buchanan;Vincent Fusco","doi":"10.1109/OJAP.2026.3673043","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3673043","url":null,"abstract":"This paper outlines the theory behind helicoid antenna array beamforming and the practical validation on an <inline-formula> <tex-math>$8times 8$ </tex-math></inline-formula> helicoid antenna array. Design, simulation, and measurement are presented at 2.45 GHz. A practical method for obtaining the phase steering weights required to perform beam pointing over 360 degrees is presented. A specialised dipole was also developed, achieving 4.9 dBi and low mutual coupling. It was also shown by analysis, simulation and measurement that this type of array, unlike a planar array, does not exhibit beam pointing error, making it highly attractive for retrodirective applications when precision beam pointing is required.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"918-925"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11430571","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148515982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Dual-Polarization Low-Profile Bifunctional Antenna Integrating Transmitarray and Fabry–Perot Resonator","authors":"Xianjiang Zhong;Xiaohang Li;He-Xiu Xu;Jianqiang Hou;Xiumei Shen;Xiaowei Shi","doi":"10.1109/OJAP.2026.3681891","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3681891","url":null,"abstract":"Attaining highly directive and integrated emissions in an antenna while simultaneously ensuring a slim profile is a challenging task. Here, we propose a novel strategy to design high gain microstrip array with dual functions, which combines the functionalities of transmitarray (TA) and Fabry-Perot resonator antenna (FPRA) at different polarization channels. First, a dual-polarized meta-atom is optimized to transmit <inline-formula> <tex-math>$x$ </tex-math></inline-formula>-polarized wave with arbitrary phase shift and partially reflect <inline-formula> <tex-math>$y$ </tex-math></inline-formula>-polarized one. Then, by arranging a set of designed meta-atoms based on a required phase distribution, a bifunctional metasurface (MS) is engineered to act as a TA and a partially reflective surface (PRS) of FPRA, simultaneously. Finally, a high gain dual-polarized array is assembled by integrating designed MS and a dual-polarized microstrip antenna as the feeding source. By altering linear polarization of the feeding source, the TA and FPRA functionalities can be flexibly switched. For verification, an antenna prototype is fabricated and measured. Both simulated and experimental results demonstrate that the antenna achieves a small height to diameter ratio of 0.2, a measured peak gain/aperture efficiency of 20.1dB/41.2% and 19.8dB/31% for TA and FPRA mode, respectively. Our proposed strategy features high gain, low profile, easy fabrication and bifunctional integration, exhibiting promising potential in future communication systems.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"976-984"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11477783","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148517333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-and Dual-Band RF-Quasi-Reflectionless Planar Monopole Antennas and Their Application to Low-Reflection Antenna Arrays","authors":"Runze Li;Li Yang;Zekai Luo;Xiu Yin Zhang;Roberto Gómez-García","doi":"10.1109/OJAP.2026.3667041","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3667041","url":null,"abstract":"An innovative family of planar monopole radiators with single- and dual-band operational characteristics and RF-quasi-reflectionless functionality is reported. 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. A multi-short-ended-stub reactive network is also employed in its input-loaded dissipative branch. Hence, under the same RF operational philosophy, low-reflection behavior through internal out-of-band RF-power dissipation can be attained at both sides of the two radiation bands with low impact on the in-band realized gains. Additionally, as a further research step, the application of the devised single/dual-band RF-quasi-reflectionless planar monopole radiators with inherent wide-band input-impedance-matching characteristics to the realization of original single/dual-frequency antenna-array architectures with RF-quasi-reflectionless properties is addressed. The RF operational foundations and design guidelines of the engineered class of single/dual-band low-reflection planar monopole radiators and their related antenna-array schemes are detailed. Furthermore, for experimental-validation purposes, a total of four proof-of-concept prototypes corresponding to 4.5-GHz single-band and 3.8/4.8-GHz dual-band RF-quasi-reflectionless planar monopole radiators and two four-element planar antenna arrays exploiting them as building blocks are designed, fabricated, and measured.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"883-899"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11406162","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148518207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multipath Measurement Leveraging In Situ Harmonic Transponders","authors":"Jeff Frolik","doi":"10.1109/OJAP.2026.3667053","DOIUrl":"https://doi.org/10.1109/OJAP.2026.3667053","url":null,"abstract":"Wireless communication within complex/cluttered environments is prone to multipath fading effects. Channel sounding are measurement techniques used to find data that characterize the extent of any such fading. Channel sounding nominally requires a transmitter at one end of the communication link and a receiving equipment at the other end. This requirement makes the measurement and characterization of cluttered, compact and/or hazardous environments challenging. In this work, we present 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 (<inline-formula> <tex-math>$f$ </tex-math></inline-formula>) and backscatter harmonics (typically, <inline-formula> <tex-math>$2f$ </tex-math></inline-formula> is of interest). However, in our work we use an amplitude modulated (AM) interrogation signal. The presented one-sided interrogation method allows one to determine the forward link loss (from the interrogator to the transponder at <inline-formula> <tex-math>$f$ </tex-math></inline-formula>), separately from reverse/backscattered link loss (from the transponder to the interrogator at <inline-formula> <tex-math>$2f$ </tex-math></inline-formula>). We demonstrate the presented approach by measuring and characterizing channel fading that is a function of frequency, space and time.","PeriodicalId":34267,"journal":{"name":"IEEE Open Journal of Antennas and Propagation","volume":"7 3","pages":"875-882"},"PeriodicalIF":3.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11406148","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148517115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}