IEEE journal of microwaves最新文献

{"title":"A New Family of Diplexers With Quarter-Wavelength Resonators and Frequency-Variant Couplings","authors":"David Rubio;Santiago Cogollos;Vicente E. Boria;Marco Guglielmi","doi":"10.1109/JMW.2026.3724678","DOIUrl":"https://doi.org/10.1109/JMW.2026.3724678","url":null,"abstract":"In this article, we discuss a novel compact topology for waveguide diplexers, composed of inline rectangular waveguide filters based on <inline-formula><tex-math>$lambda _{g}/4$</tex-math></inline-formula> resonators and frequency-variant couplings (FVCs). The FVCs also generate transmission zeros (TZs), thereby significantly enhancing the filters’ selectivity. The theory needed for the accurate synthesis and design of the waveguide structure is explained in detail. We also describe, step by step, the design of the two separate filters and the procedure to combine them into a diplexer. Finally, we discuss the measured results of a Ku-band diplexer prototype. The measured results are in very good agreement with theory, thereby validating both the new topology and the design procedure that we describe.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1299-1315"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11683957","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011260","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 Compact, Enhanced Gain and Dual Band Antenna Array for a Cardiac Loop Recorder Device","authors":"Deepti Sharma;Rakesh Nath Tiwari;Sachin Kumar","doi":"10.1109/JMW.2026.3710609","DOIUrl":"https://doi.org/10.1109/JMW.2026.3710609","url":null,"abstract":"An implantable cardiac loop recorder (ICLR) is a compact device that detects arrhythmias and syncope by continuously monitoring the heart’s electrical activity. The present research introduces a compact enhanced gain 4 × 2 antenna array for an ICLR device to transmit heart health data to remote physicians. The antenna array has a compact footprint of 4 mm × 7 mm and provides dual-band biotelemetry at the industrial, scientific, and medical (ISM) frequencies of 2.4 GHz and 5.8 GHz. In the simulation environment, the ICLR integrated antenna array is designed by implanting under the skin of a skin-blood-fat-muscle canonical chest phantom model and a 3D homogeneous human body model. The performance of the designed antenna array is experimentally evaluated in a gel-based skin phantom and minced pork. The simulated and measured gain values at 2.4 GHz are −17.82 dBi and −20.1 dBi, while at 5.8 GHz are −9.5 dBi and −12.3 dBi, respectively. The literature review highlights that the novelty of this research lies in a compact dual-band implantable antenna, with enhanced gain achieved through a 4 × 2 array design incorporating two distinct ultra-compact antenna elements. The achieved gain is higher than previously reported implanted antennas of comparable footprints. The authors additionally investigated the impact of different biological layers on the propagation of the antenna’s transmitted wave inside the human body, which was not discussed in prior studies on implantable antennas. The link margin indicates that the proposed ICLR biotelemetry antenna can effectively communicate up to 5 meters of distance at 10 Mbps data rates non-line of sight communication scenarios.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1144-1159"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11623052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011393","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":"Efficient Integral Equation Technique for the Analysis of Rectangular Waveguides Microwave Circuits Loaded With 3D Homogeneous and Conducting Objects","authors":"Antonio Manuel Huéscar de la Cruz;Antonio Oliva Aparicio;Fernando D. Quesada Pereira;Alejandro Álvarez Melcón;Vicente E. Boria Esbert","doi":"10.1109/JMW.2026.3720973","DOIUrl":"https://doi.org/10.1109/JMW.2026.3720973","url":null,"abstract":"This contribution presents an efficient analysis of microwave circuits, in rectangular waveguide technology, containing an unlimited number of arbitrarily shaped 3D conducting and lossy homogeneous dielectric and/or magnetic material objects. The proposed method uses the Electric Field Integral Equation (EFIE) combined with the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) formulation, employing frequency-domain Lorenz gauge Green’s functions and their spatial derivatives accelerated by the Ewald method. To enhance computational performance, the Method of Moments (MoM) matrices are divided into dynamic and static components. Unlike free-space problems, the rectangular waveguide environment presents the technical challenge of evaluating a series of specific terms for homogeneous objects. Furthermore, to reduce the computational cost, an adaptive numerical integration scheme is implemented that dynamically adjusts the number of integration points based on the distance between the source and observation points. A further novelty in the application of the PMCHWT formulation occurs when homogeneous objects are in contact with the waveguide boundaries. In such instances, the equivalent internal problem is addressed by applying image theory to the free-space Green’s functions relative to the waveguide walls. Finally, the proposed integral equation technique is validated against the commercial full-wave solver Ansys HFSS, demonstrating excellent agreement as well as a reduction in computation time and memory consumption.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1407-1420"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11661594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011198","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":"Corneal Dosimetry in the 200–500 GHz Band Using Generalized Lorenz–Mie Theory","authors":"Roman Grigorev;Faezeh Zarrinkhat;Joel Lamberg;Mikhail Sidorenko;Lufang Guo;Viktar S. Asadchy;Zachary Taylor","doi":"10.1109/JMW.2026.3727126","DOIUrl":"https://doi.org/10.1109/JMW.2026.3727126","url":null,"abstract":"This study presents a comprehensive dosimetric analysis of the human cornea exposed to continuous radiation in the 200–500 GHz frequency range. A semi-analytic approach is developed by combining Bruggeman effective-medium theory of the hydration-graded cornea with Generalized Lorenz–Mie Theory (GLMT) for arbitrary Gaussian-beam illumination, coupled to a Pennes bioheat equation to compute SAR, absorbed power density (<inline-formula><tex-math>$S_{ab}$</tex-math></inline-formula>) averaged over <inline-formula><tex-math>$1;mathrm{cm^{2}}$</tex-math></inline-formula>, and the temperature rise <inline-formula><tex-math>$Delta T$</tex-math></inline-formula>. Validation at 100 GHz against established plane-wave results is obtained in the large-waist limit (<inline-formula><tex-math>$w_{0} = text{60};text{mm}$</tex-math></inline-formula>). Across 200–500 GHz at <inline-formula><tex-math>$w_{0} = text{3};text{mm}$</tex-math></inline-formula>, <inline-formula><tex-math>$S_{ab}$</tex-math></inline-formula> and both peak and average temperature rises increase modestly with frequency, whereas the heating factor <inline-formula><tex-math>$Delta T_{text{peak}}/S_{ab}$</tex-math></inline-formula> varies by less than 0.3%, establishing <inline-formula><tex-math>$S_{ab}$</tex-math></inline-formula> as a frequency-stable surrogate for peak corneal temperature in this band. A beam-size sweep at <inline-formula><tex-math>$text{300};text{GHz}$</tex-math></inline-formula> (<inline-formula><tex-math>$w_{0} = 2$</tex-math></inline-formula>–<inline-formula><tex-math>$text{12};text{mm}$</tex-math></inline-formula>) at fixed aperture-averaged incident power density demonstrates that beam geometry is the dominant determinant of peak corneal heating: <inline-formula><tex-math>$Delta T_{text{peak}}$</tex-math></inline-formula> decreases by roughly a factor of four as the waist increases, while <inline-formula><tex-math>$S_{ab}$</tex-math></inline-formula> increases only slightly. Peak and area-averaged quantities therefore vary in opposite directions as the beam narrows. Across all configurations, the calculated metrics at reference incident power densities of <inline-formula><tex-math>$40;mathrm{W/m^{2}}$</tex-math></inline-formula> remain more than an order of magnitude below the <inline-formula><tex-math>$5;^{circ }mathrm{C}$</tex-math></inline-formula> Type-1 corneal operational threshold, and no abrupt change in dosimetric behaviour is observed across <inline-formula><tex-math>$text{300};text{GHz}$</tex-math></inline-formula>. Presented results quantify, for the cornea at sub-terahertz frequencies, the beam-size regime in which area-averaged <inline-formula><tex-math>$S_{ab}$</tex-math></inline-formula> and local peak corneal temperature diverge.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1132-1143"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11700402","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011291","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 New Layout for GaN-on-SiC HEMTs With Enhanced RF and Thermal Performance","authors":"Erdem Aras;Bayram Butun;Ekmel Ozbay;Abdullah Atalar","doi":"10.1109/JMW.2026.3718815","DOIUrl":"https://doi.org/10.1109/JMW.2026.3718815","url":null,"abstract":"Gallium nitride on silicon carbide (GaN-on-SiC) high-electron-mobility transistors (HEMTs) require low source-to-ground inductance, compact layout footprint, and reduced channel temperature for radio-frequency (RF) power applications. This work introduces a double-sided source-via (DSSV) HEMT layout that places source vias on both the gate and drain sides of the active region, increasing the number of vias per unit transistor cell. Using a 0.25 μm GaN-on-SiC technology, 6 × 100 μm and 10 × 100 μm HEMTs were fabricated and benchmarked against individual-source-via (ISV), outer-source-via (OSV), and side-source-via (SSV) layouts. Compared with ISV, DSSV reduces the y-dimension by 31.7% for the 6-gate cell and by 44.2% for the 10-gate cell. At 18 GHz, DSSV achieves measured maximum available/stable gain values of 14.3 dB and 12.3 dB for the 6-gate and 10-gate devices, respectively, matching the corresponding ISV HEMTs. Large-signal load-pull measurements at 12 GHz show comparable saturated output power and drain efficiency across layouts: 35.2–35.4 dBm with 50–52% drain efficiency for the 6-gate devices and 37.8–38.0 dBm with 52–55% drain efficiency for the 10-gate devices with maximum-output-power load impedance. For equal-y-dimension 10-gate devices, DSSV reduces the channel temperature by 15 <inline-formula><tex-math>$^{circ }$</tex-math></inline-formula>C while the small-signal gain is reduced by 0.5 dB. Based on an Arrhenius model, this temperature reduction predicts a 2.1–3.8× lifetime improvement.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1350-1358"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11655566","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011199","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":"Wideband (2:1) Phase Shifter for Reconfigurable Intelligent Surfaces With Linear Phase Control","authors":"Tatiana Valera;Stavros Koulouridis;Michail O. Anastasiadis;Satheesh B. Venkatakrishnan;John L. Volakis","doi":"10.1109/JMW.2026.3710607","DOIUrl":"https://doi.org/10.1109/JMW.2026.3710607","url":null,"abstract":"This paper presents a novel wideband phase shifter that utilizes an elliptically shaped slot-based topology for millimeter wave (mm-Wave) Reconfigurable Intelligent Surfaces (RIS). The proposed design is implemented on a multi-layer PCB and operates across 15 GHz to 30 GHz with minimal phase error. The phase shifter employs umbrella-loaded elliptical slots and patches to achieve a stable differential phase shift across 2:1 bandwidth. At the same time, the ellipsoidal elements maintain a low-loss response. Moreover, the proposed miniature phase shifter (5 mm x 5 mm) can be readily incorporated into the limited space of the RIS unit element. The proposed concept is validated via fabrication and characterization of a prototype. Specifically, the measurements demonstrated a stable 2:1 bandwidth operation with phase errors of less than 7<inline-formula><tex-math>$^{circ }$</tex-math></inline-formula> across the entire band. The proposed phase shifter maximizes gain and minimizes beam-steering errors across large bandwidth, using a 1-bit RIS. To the best of the author’s knowledge, this is the first design to monstrate 2:1 bandwidth with stable phase for RIS applications.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1359-1369"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11640858","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011205","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 120-GHz Oversampling Digital-to-Phase Transmit Array for Integrated Sensing and Communications","authors":"Justin J. Kim;Alex Dinkelacker;Nuutti Tervo;James F. Buckwalter","doi":"10.1109/JMW.2026.3713399","DOIUrl":"https://doi.org/10.1109/JMW.2026.3713399","url":null,"abstract":"A digital transmit array technique is proposed using constant-envelope circuit architectures with state-of-the-art efficiency. Using 2-bit phase shifters that can oversample the signal at gigasample-per-second rates in each channel, the digital-to-phase modulation enables simultaneous beam-steering and waveform generation through spatial and temporal power combining. The prototype 4-channel transmitter (TX) is fabricated in a 22-nm FD-SOI CMOS technology, flip-chip mounted onto a Low-Temperature Co-fired Ceramic (LTCC) interposer with integrated Vivaldi antennas, and wire-bonded to a PCB. The TX array operates from 110 to 122 GHz and exhibits a measured peak effective isotropic radiated power (EIRP) of 29.5 dBm with <inline-formula><tex-math>$pm$</tex-math></inline-formula>25^o of scanning range and 6.7% TX channel efficiency. Using a linear combinations of channels, a 250-Mbps, 32-QAM waveform is demonstrated with 13% EVM through oversampling and spatial calibration of the low-resolution phase shifters. Frequency-modulated continuous wave (FMCW) radar is demonstrated to realize a 3.1 cm range resolution. The oversampling digital-to-phase (ODP) architecture is a viable solution for scalable millimeter-wave (mm-wave) integrated sensing and communication (ISAC).","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1316-1328"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11635829","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011322","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":"FFTFormer: A Frequency-Aware Transformer With Multi-Task Learning for Robust Modulation Recognition","authors":"Daying Quan;Yi Chen;Yulin Sun;Jun Zhao;Ning Jin;Xiaofeng Wang;Xianhui Liu","doi":"10.1109/JMW.2026.3706228","DOIUrl":"https://doi.org/10.1109/JMW.2026.3706228","url":null,"abstract":"Automatic Modulation Recognition (AMR) is a key enabler of intelligent signal processing in modern wireless communication systems. Although deep learning (DL)-based approaches have achieved notable progress, their performance often degrades at low signal-to-noise ratios (SNRs). Furthermore, most existing studies assume fixed roll-off factors during pulse shaping, overlooking the inherent variability of real-world signals, and thus overestimating model robustness. To address these limitations, this paper proposes FFTFormer, a frequency-aware Transformer that integrates a Fast Fourier Transform (FFT)-driven attention mechanism with a frequency-adaptive feedforward network to enhance the learning of modulation features in the frequency domain. By transforming token representations into spectral components, FFTFormer effectively captures modulation-specific spectral dependencies and improves recognition performance in low SNR environments. Moreover, considering the significant influence of the root-raised cosine (RRC) filter's roll-off factor on signal features, an auxiliary roll-off factor prediction task is introduced to guide the adaptive learning of spectral variations across diverse pulse-shaping conditions, thereby enhancing the model's robustness and generalization. Experimental results on the RML16 A and RML22 datasets demonstrate that FFTFormer significantly outperforms state-of-the-art (SOTA) DL-AMR models. Under low SNR conditions, FFTFormer surpasses the best-performing SOTA baselines by 2.36% and 2.83%, respectively. Furthermore, we have verified the effectiveness of the proposed FFTFormer using actual measurement data, emphasizing its practical applicability.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1421-1439"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11593936","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011356","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":"PA-Aware Partially-Connected Hybrid Beamforming Design for Wideband Integrated Sensing and Communication","authors":"Mengyu Zhang;Tianzhu Huang;Torsten Reissland;Timo Maiwald;Norman Franchi;Robert Weigel","doi":"10.1109/JMW.2026.3728101","DOIUrl":"https://doi.org/10.1109/JMW.2026.3728101","url":null,"abstract":"Integrated sensing and communication (ISAC) systems operating in the millimeter-wave (mmWave) spectrum critically depend on hybrid beamforming (HBF) architectures to achieve an effective trade-off between hardware implementation complexity and beamforming flexibility. However, the nonlinear behavior of power amplifiers (PAs) can significantly degrade system performance, especially in wideband OFDM transmission, where high peak-to-average power ratios and frequency-dependent PA responses introduce additional distortion. Most existing HBF designs either compensate for nonlinear distortion through predistortion techniques or impose simple transmit power constraints, which do not explicitly regulate the PA’s operating region. This paper proposes a PA-aware hybrid beamforming framework that explicitly incorporates PA characteristics into the precoder design. A soft operating-region constraint, derived from the statistical distribution of the OFDM input power, is introduced to regulate the excitation level of each RF chain. This constraint facilitates an optimal trade-off between power efficiency and linearity, while mitigating excessive distortion caused by compression. In addition, a lightweight frequency-domain compensation mechanism is developed to mitigate frequency-selective amplitude distortion in wideband transmissions. The proposed framework operates entirely in the digital precoding domain and therefore does not require additional RF hardware modification. Its effectiveness is validated through system-level simulations using both parameterized PA models and measurement-based PA characteristics, demonstrating robust distortion-aware performance under realistic hardware conditions.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"1285-1298"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11683956","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011417","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":"IEEE Microwave Theory and Technology Society Publication Information","authors":"","doi":"10.1109/JMW.2026.3727794","DOIUrl":"https://doi.org/10.1109/JMW.2026.3727794","url":null,"abstract":"","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 5","pages":"C2-C2"},"PeriodicalIF":4.5,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11700404","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149011207","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}