IEEE journal of microwaves最新文献

{"title":"Coaxial to Empty Substrate Integrated Waveguide Transition for Small Satellite Microwave Technology","authors":"Laura Rivero;David Herraiz-Zanon;Ignacio Galeote;Hector Esteban;Angel Belenguer;Vicente E. Boria","doi":"10.1109/JMW.2026.3661766","DOIUrl":"https://doi.org/10.1109/JMW.2026.3661766","url":null,"abstract":"Empty Substrate Integrated Waveguides (ESIW) integrate hollow 3D waveguide structures into printed circuit boards (PCBs), providing a compact, low profile, and low cost solution that can be easily connected to other circuits in the same PCB. Several transitions have been proposed to connect ESIW circuits to planar (microstrip or coplanar) lines. However, these transitions require complex manufacturing processes and are not directly compatible with standard measurement equipment, thus requiring additional transitions from the planar line to the coaxial probes of the network analyzer. This induces degradation in electrical performance due to the presence of multiple transitions. Therefore, the present work proposes two novel coaxial-to-ESIW transition designs based on magnetic coupling. The proposed structures offer a design process including an equivalent circuit model and a significantly simplified fabrication, relying solely on basic cutting and metallization processes. Both transitions achieve measured insertion losses of 1 dB and 0.7 dB, respectively, while also reaching measured return losses of 12.5 dB.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"429-440"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11398114","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148510885","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":"Strong Collective Responses in Quasi-1D Metadevices for Millimeter-Wave Electronics","authors":"Abdallah Abushawish;Ziwen Huang;Mohammad Samizadeh Nikoo","doi":"10.1109/JMW.2026.3651502","DOIUrl":"https://doi.org/10.1109/JMW.2026.3651502","url":null,"abstract":"Quasi-1D electronic metadevices, which utilize periodic arrays of subwavelength metallic structures to enhance high-frequency electrical performance, have shown promise for ultrafast integrated electronics. Here, we present theoretical, numerical, and experimental evidence revealing pronounced collective responses in such structures at deep subwavelength scales. We demonstrate that as the feature size is reduced to well below the artificial wavelength, altering the number of features strongly affects the microscopic current density, resulting in drastic measurable shifts in macroscopic properties. We show that increasing the number of stripes in deep-subwavelength quasi-1D metadevices results in up to 4 times decrease in the normalized contact resistance, which considerably improves the switching cutoff frequency of the device. Furthermore, while shrinking subwavelength elements can improve high-frequency electrical characteristics, achieving asymptotic performance requires a sufficiently large number of these features—a number that is inversely proportional to the feature size. Our findings offer deeper insights into the underlying physics of metadevices and chart a path toward further performance enhancement, with implications for high-speed telecommunications.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"410-417"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11363083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148510888","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":"Leadless Pacemakers: Past, Present, and Future—A Review of Antennas and Wireless Power and Data Telemetry","authors":"Deepti Sharma;Toni Björninen;Rakesh Nath Tiwari","doi":"10.1109/JMW.2026.3663222","DOIUrl":"https://doi.org/10.1109/JMW.2026.3663222","url":null,"abstract":"The leadless cardiac pacemaker is a revolutionary device for bradycardia patients. It is a single-component, capsule-type implantable medical device that corrects the heart's electrical function when the heart rate falls below the standard value of 60 beats per minute. The remote monitoring feature enables the leadless pacemaker to monitor bradycardia patients’ heart health, and it is only possible due to the ultra-compact antenna of the implantable leadless pacemaker's biotelemetry system. This article reviews the leadless pacemaker's antennas for biotelemetry and power telemetry systems, the importance of intra-cardiac communication for dual-chamber leadless pacemakers, and future requirements of leadless pacemaker antennas. Considering the real-time device architecture, some crucial aspects of antenna design in the simulator are given by briefing the research conducted to date. Furthermore, experimental verification of the antenna's functioning in the cardiac environment is also provided by summarizing different approaches used by previous studies. Dual-chamber leadless pacing communication and the requirement of leadless pacemaker antennas in 5G/6G IoT healthcare environment are also briefly discussed.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"574-587"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11413924","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147558049","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 Novel Framework for Realistic 3D Skin Modeling and its Exposure to Millimeter Waves","authors":"Serafeim Iakovidis;Athanasios Manassas;Myles Capstick;Christine Pich-Bavastro;Zhouxing Su;Dorothea Kapoukranidou;Olivier Gaide;Theodoros Samaras","doi":"10.1109/JMW.2026.3684941","DOIUrl":"https://doi.org/10.1109/JMW.2026.3684941","url":null,"abstract":"Millimeter wave (MMW) technology is increasingly used in telecommunications and medical applications, necessitating a deeper understanding of its interaction with human tissue, particularly skin. The limited penetration depth of MMWs makes the skin the primary site of energy absorption, requiring detailed dosimetric analysis. Traditional skin models often assume planar, layered structures, neglecting the natural undulating geometry of the epidermis and dermis. This study introduces a novel methodological framework for constructing realistic three-dimensional (3D) human skin models using Optical Coherence Tomography (OCT) and Ultrasound (US) imaging. The framework involves three key steps: (1) OCT and US image acquisition, (2) image segmentation and processing, and (3) synthesis of processed data to generate high-fidelity 3D skin models. Three anatomical sites—the volar forearm, hypothenar region, and fingertip—were selected for model development, representing variations in skin roughness and layer composition. The dielectric properties of the skin and subcutaneous layers were incorporated into finite-difference time-domain (FDTD) simulations at 27.5 GHz to evaluate the impact of skin roughness on electromagnetic field distribution. Our results demonstrate that the natural undulations of the dermoepidermal junction and air-skin interface significantly affect MMW energy absorption patterns. The roughness of these interfaces varies across anatomical sites, influencing local electric field distributions and leading to deviations from predictions based on planar models. The findings suggest that incorporating realistic skin geometries enhances dosimetric accuracy, which is critical for both safety assessments and optimizing MMW-based medical applications. This study provides an approach for individualized MMW dosimetry and underscores the importance of considering anatomical variations in electromagnetic exposure assessments. The framework was additionally extended to a nodular basal cell carcinoma case, revealing marginal changes in local field and SAR distributions and a moderate increase in reflected power compared to healthy skin.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"641-652"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11506041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828995","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 Highly Compact 530-610 GHz Bandpass Filter Using Patch Resonators to Develop SSB Spectrometer","authors":"Berhanu T Bulcha;Diego Tononi;Thomas R. Stevenson;Edward J. Wollack","doi":"10.1109/JMW.2026.3685154","DOIUrl":"https://doi.org/10.1109/JMW.2026.3685154","url":null,"abstract":"In double sideband (DSB) receiver systems, both the desired signals and unwanted image frequencies are downconverted, necessitating effective filtering to enhance system selectivity and sensitivity. This manuscript presents a novel submillimeter-wave bandpass filter developed to suppress the unwanted image frequencies in a spectrometer system that is optimized to detect key atmospheric constituents in the passband, including water vapor (H₂¹⁶O – 559.9 GHz), deuterium oxide (HDO – 539.0 GHz), and oxygen (O₃ – 570.1 GHz). The filter design employs compact triangular microstrip patch resonators that achieve sharp roll-off characteristics and wide stopband performance, making it ideal for image rejection applications across submillimeter-wave and THz bands. The filter is fabricated on a 15 μm quartz substrate with 0.5 μm gold metallization, providing a 3 dB bandwidth of approximately 80 GHz with well-defined rejection bands below 530 GHz and above 610 GHz. Signal coupling is accomplished through microstrip waveguide feed probes for input and output. The design methodology offers significant flexibility, allowing straightforward scaling and adjustment of center frequency and bandwidth for implementations ranging from 1 GHz to 2 THz. The versatility of the filter architecture presented has utility in radio astronomy, defense systems, and high-frequency communication network applications.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"766-773"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11513288","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828996","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 Noninvasive and Dispersive Framework for Estimating Nonuniform Conductivity of Brain Tumor in Patient-Specific Head Models","authors":"Yoshiki Kubota;Yosuke Nagata;Manabu Tamura;Akimasa Hirata","doi":"10.1109/JMW.2026.3681237","DOIUrl":"https://doi.org/10.1109/JMW.2026.3681237","url":null,"abstract":"We propose a noninvasive and dispersive framework for estimating the spatially nonuniform conductivity of brain tumors using MR images. The method consists of two components: (i) voxel-wise assignment of tumor conductivity based on reference values fitted to the Cole–Cole model using empirical data from the literature and (ii) fine-tuning of a deep learning model pretrained on healthy participants A total of 67 cases, comprising both healthy participants and tumor patients and including 9,806 paired T1- and T2-weighted MR images, were used for training and evaluation. The proposed method successfully estimated patient-specific conductivity maps, exhibiting smooth spatial variations that reflected tissue characteristics, such as edema, necrosis, and rim-associated intensity gradients observed in T1- and T2-weighted MR images. At 10 kHz, case-wise mean conductivity values varied across patients, ranging from 0.132 to 0.512 S/m in the rim (defined as the region within 2 mm of the tumor boundary), from 0.132 to 0.608 S/m in the core (the area inside the rim), and from 0.141 to 0.542 S/m in the entire tumor. Electromagnetic simulations for transcranial magnetic stimulation in individualized head models showed substantial differences in intratumoral field distributions between uniform assignments and the proposed nonuniform maps. Furthermore, the proposed framework enables voxel-wise conductivity mapping across multiple frequencies (10 kHz, 1 MHz, and 100 MHz) by combining spatially resolved conductivity estimation with a physics-informed dispersive scaling model. This framework supports accurate whole-brain conductivity estimation by incorporating both individual anatomical structures and tumor-specific characteristics. Collectively, these results advance patient-specific EM modeling for tumor-bearing brains and lay the groundwork for subsequent validation in higher-frequency electromagnetic applications.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"653-663"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11491847","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828997","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 High-Power Frequency Doubler-Based Terahertz Frequency-Modulated Continuous-Wave Transceiver Front-End","authors":"Xuan Sheng;Ziqiang Yang;Hongyu Bao;Lian Hu;Yazhou Dong;Huajie Liang;Shixiong Liang;Ziqiang Yang;Yaxin Zhang","doi":"10.1109/JMW.2026.3670855","DOIUrl":"https://doi.org/10.1109/JMW.2026.3670855","url":null,"abstract":"This paper presents a high-performance terahertz frequency-modulated continuous-wave (FMCW) transceiver front-end operating at 139.5–148.5 GHz, which leverages a high-power frequency doubler to address critical challenges in terahertz amplification. A novel modular architecture is introduced to circumvent the limitations of power amplifiers (PAs), enabling a breakthrough in power handling capability. In the transmitter, a GaN Schottky diode-based doubler integrated with meta-atom resonant microstructures achieves an output power exceeding 17 dBm by enhancing electric field coupling and power conversion efficiency. The receiver employs a custom subharmonic mixer combined with a low-noise amplifier (LNA) placed adjacent to the feed source, effectively reducing the noise figure. A compact waveguide-to-microstrip transition and cavity filter assembly in the system packaging suppresses spurious emissions below −43.84 dBc. Experimental results demonstrate an input P1dB of −22.5 dBm (surpassing the −24 dBm specification), with a switchable IF bandwidth (50/90 MHz modes) for adaptive ranging. The total gain reaches 85.36 dB, and the manual gain control (MGC) accuracy achieves 0.515 dB RMS. The front-end balances power efficiency, spectral purity (phase noise ≤−92.5 dBc/Hz at 1 kHz), and linearity, providing a reliable hardware platform for high-resolution radar imaging, non-destructive testing, and real-time sensing applications.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"698-710"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11454698","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829009","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":"Miniaturized Ultrawide Stopband Single-Band Filter and Large Frequency Ratio Dual-Band Filter Based on Inhomogeneous Half-Mode T-Septum Waveguide","authors":"Zi-Qi Zhang;Liang Zhou","doi":"10.1109/JMW.2025.3649706","DOIUrl":"https://doi.org/10.1109/JMW.2025.3649706","url":null,"abstract":"The inhomogeneous half-mode T-septum waveguide (IHMTSG) cavity is analyzed and applied to the design of miniaturized single- and dual-band band-pass filters (BPFs) in this paper. A defected microstrip structure (DMS) is utilized to achieve ultrawide stopband suppression while preserving transmission characteristics through its band-notched effect. The synthesized, simulated, and measured <italic>S</i>-parameters of the single- and dual-band BPFs show good agreement. The fabricated single-band BPF operates at 5.8 GHz (<italic>f</i>₁) with a 3-dB bandwidth of 9.5% is designed for n46 frequency range, while the dual-band BPF operates at 4.69/25.95 GHz (<italic>f</i>₁/<italic>f</i>₂) with 3-dB bandwidths of 16.8% and 14.73% is designed for n79/n258 in 5G application, respectively. Excellent upper stopband rejection is achieved, with suppression levels of 20 dB extending up to 9.3<italic>f</i>₁ in the single-band BPF and 11.3<italic>f</i>₁ in the dual-band BPF, without spurious modes in the mid-band region. The dual-band BPF achieves a large frequency ratio of 5.53. The proposed single- and dual-band BPFs exhibit competitive performance in terms of miniaturization, ultrawide stopband, and high frequency selectivity with clean mid-band characteristics using the in-house silicon-based MEMS photosensitive composite film fabrication process compared with state-of-the-art filters.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"475-488"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11357956","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148511266","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":"Multi-Feed Holographic-Based Leaky Wave Antennas for MIMO-Radar Applications","authors":"Thomas Frey;Nico Riese;Dominik Schwarz;Maximilian Döring;Christian Waldschmidt;Tobias Chaloun","doi":"10.1109/JMW.2026.3658926","DOIUrl":"https://doi.org/10.1109/JMW.2026.3658926","url":null,"abstract":"This paper presents the integration and experimental validation of a multi-feed holographic-based leaky wave antenna (HLWA) array into an automotive MIMO radar system. First, a novel multi-layer integration concept with a quasi-coaxial transition is designed and fabricated, enabling rotationally symmetric surface wave excitation. Measured S-parameters from 76 GHz to 81 GHz show reflection coefficients below −10 dB and inter-port coupling <−22><tex-math>$lambda _{0}$</tex-math></inline-formula> across the automotive band. A wide beam synthesis process, fully decoupled from the antenna aperture size, is implemented by modifying the transverse modulation period of the surface impedance hologram. To combine multiple Tx and Rx sub-holograms into a shared holographic aperture, an angular-dependent hologram synthesis method is employed. The realized MIMO-HLWA array is fabricated on a fused silica wafer and comprises three Tx and four Rx feeds, resulting in a virtual aperture size of 6.5 <inline-formula><tex-math>$lambda _{0}$</tex-math></inline-formula>. Radar measurements of the MIMO-HLWA system in an anechoic chamber yield an ambiguity-free region of 21° × 21°. Subsequent validation scenarios demonstrate precise angular detection of multiple static targets and an average power improvement of 10 dB in range spectrum compared to the reference array is achieved. Moreover, dynamic scenarios involving one and two pedestrians verify the capability to resolve Doppler spectrograms clearly.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"298-311"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11393897","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148511260","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":"Call for Papers—IEEE Journal of Microwaves Special Issue Celebrating the 75th Anniversary of the Microwave Theory and Technology Society: “Microwaves are Everywhere”","authors":"","doi":"10.1109/JMW.2026.3672955","DOIUrl":"https://doi.org/10.1109/JMW.2026.3672955","url":null,"abstract":"","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"495-495"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11437565","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148512337","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}