IEEE journal of microwaves最新文献

{"title":"Machine Learning-Driven Space Mapping for Microwave Filter Parameter Extraction With Small Datasets","authors":"Olufemi Oluyemi;Paul Laforge;Abdul Bais","doi":"10.1109/JMW.2026.3681924","DOIUrl":"https://doi.org/10.1109/JMW.2026.3681924","url":null,"abstract":"Space mapping is a powerful optimization technique that reduces computational effort by leveraging surrogate models. However, parameter extraction within a space-mapping framework can remain computationally demanding, especially for complex structures at the coarse-model level. This research introduces a convolutional neural network–based approach for parameter extraction that is seamlessly integrated into the space-mapping workflow. We employ sensitivity analysis to identify the parameters that most strongly influence the optimization outcome, enabling the construction of compact yet informative training datasets. The resulting model adapts well across frequency ranges represented in the generated data and is demonstrated on microstrip filter designs with and without cross-coupling. Compared with traditional circuit-level optimization, the proposed approach yields substantial time savings: reductions by factors of 2.0 to 2.7 for single designs and 8.0 to 10.7 for multiple designs. These results indicate that learning-driven parameter extraction can mitigate a key bottleneck in space mapping, paving the way for faster, more scalable microwave filter design while preserving accuracy at both coarse and fine model levels.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"774-785"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11501403","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828948","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":"Experimental Validation of Thermoregulatory Modeling for Human Back Exposure at 28 GHz","authors":"Shoma Kato;Akimasa Hirata;Hiroshi Masuda;Akiko Matsumoto;Sachiko Kodera","doi":"10.1109/JMW.2026.3662329","DOIUrl":"https://doi.org/10.1109/JMW.2026.3662329","url":null,"abstract":"This study investigates skin temperature rise during dorsal exposure to 28 GHz quasi-millimeter waves using an electromagnetic–thermal computational modeling framework considering thermoregulation. Human exposure experiments were numerically reproduced using anatomically detailed models of Japanese adults augmented with age- and sex-related thermoregulatory functions. An exposure system with dielectric lens antennas provided controlled irradiation to the back, and the measured skin temperatures were compared with the computational predictions. The computational framework reproduced the experimental temperature rises well for both the 64-region of interest (ROI) and 1-ROI. Furthermore, the model reproduced the tendency that female participants exhibited higher temperature rises than males, which was mainly attributed to anatomical variations in muscle and fat composition. Age-related effects were modest, likely because the older adult group was approximately 65 years old. The predicted temperature rise was 2.48 °C, which is within the permissible limit of 2.5 °C (derived from the operational threshold of 5 °C with a reduction factor of 2) when evaluated at an absorbed power density of 100 W/m² for occupational exposure, as specified in international exposure guidelines. These findings demonstrate the applicability of the thermoregulatory model to superficial absorption for exposure to quasi- and millimeter waves and support its use for assessment across different populations, such as those differing in age, sex, and thermoregulatory capacity.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"519-530"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11410436","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557565","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":"Model Variability in Assessment of Human Exposure to Radiofrequency Fields","authors":"Akimasa Hirata;Ilkka Laakso;Francesca Apollonio;Sachiko Kodera;Yoshiki Kubota;Junqing Lan;Kun Li;Micaela Liberti;Dragan Poljak;Kensuke Sasaki;Maxim Zhadobov;Yinliang Diao","doi":"10.1109/JMW.2025.3628902","DOIUrl":"https://doi.org/10.1109/JMW.2025.3628902","url":null,"abstract":"The recent advances in computational dosimetry for electromagnetics and thermodynamics are reviewed to assess human exposure to electromagnetic fields in the MHz-to-terahertz range. This review emphasizes model variability in computational dosimetry. Apart from computational electromagnetic methods and their usage, the developments in anatomical phantoms and tissue dielectric properties characterization are also surveyed. In addition, the rationale for dosimetric quantities prescribed in international exposure guidelines, such as the specific absorption rate (SAR) and absorbed power density, is revisited in relation to their correlation with local and core temperature rises in various tissues and populations. A heating factor, which is defined as a steady-state temperature rise per SAR, for the brain, eye lens, skin, and body core is evaluated to estimate heating resulting from exposure to electromagnetic fields. The transition of a physical quantity in the guidelines at 6 GHz, from SAR to the absorbed power density, is discussed along with the optimal spatial averaging volume and areas. Computational evaluations of product compliance, 5G devices, and wireless power transfer systems are also reviewed. This review aims to synthesize the current knowledge, identify key sources of computational model variability and uncertainty, and outline further research needs for setting exposure guidelines and compliance assessment.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"502-518"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11269783","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147558053","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":"Sub-THz Signal Distribution Based on Additively Manufactured Dielectric Image Lines","authors":"Leonhard Hahn;Lukas Bürk;Tobias Bader;David Panusch;Christian Carlowitz;Gerald Gold;Martin Vossiek","doi":"10.1109/JMW.2026.3682062","DOIUrl":"https://doi.org/10.1109/JMW.2026.3682062","url":null,"abstract":"The realization of low-loss multi-channel power splitters at sub-THz frequencies is highly challenging, as conventional transmission-line-based approaches suffer from severe performance limitations, low scalability, or high fabrication costs. To illustrate an attractive solution to this problem, this work presents a broadband sub-THz signal distribution network based on additively manufactured dielectric image lines (DIL), enabling symmetric 1x6 power splitting across the 140–220 GHz range. For the first time, additive manufacturing (AM) is used to integrate various dielectric components like transmission lines, 1x2 and 1x4 splitters, a directional coupler with configurable power division ratio, and a dielectric termination into a large-scale, monolithic network. The concept is manufactured using up to four different AM techniques to investigate the impact of fabrication characteristics on network performance. Manufacturing artifacts are analyzed and modeled, revealing the impact of adhesion, surface quality, and process complexity onto key performance metrics like efficiency, bandwidth, port symmetry, and reproducibility.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"738-753"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11495100","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828957","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":"Development of a Bespoke Hybrid Electron Paramagnetic Resonance (EPR) Spectrometer for Simultaneous In Situ Neutron Diffraction Studies","authors":"Kai Silver;Heungjae Choi;Michael Barter;Steve C. Cripps;Ron I. Smith;Emma Richards;Damien M. Murphy;Martin O. Jones;Adrian Porch","doi":"10.1109/JMW.2026.3686727","DOIUrl":"https://doi.org/10.1109/JMW.2026.3686727","url":null,"abstract":"We present the design, construction, and commissioning of the first hybrid Electron Paramagnetic Resonance (EPR) spectrometer engineered to operate within a Neutron Powder Diffractometer (NPD), enabling simultaneous measurements of spin properties and crystal structure. Developed for the Polaris instrument at the ISIS Neutron and Muon Source (U.K.), the system was specifically designed to function within the constraints of a neutron beamline. Achieving in situ EPR capability within the diffractometer required several necessary compromises to the diffraction geometry. The finite gap between the two halves of the electromagnet body reduces detector visibility, limiting coverage for a proportion of scattering angles. The retained magnetic return-path introduce restricted regions in 2<inline-formula><tex-math>$theta$</tex-math></inline-formula> that require reorientation of the instrument to access. Furthermore, the change in sample geometry from a conventional vertical cylindrical configuration to a skewed horizontal cylinder had a detrimental effect on diffraction peak shape and width. The aluminium microwave cavity, although thinned to 0.1 mm to maximise neutron transparency, introduces additional background Bragg reflections. Despite these trade-offs, simultaneous EPR and neutron diffraction data were successfully acquired. Key innovations include a bespoke electromagnet compatible with beamline access, a thinwalled X-band quasi-elliptical microwave cavity, a remotely tuneable waveguide coupling scheme, and a modular support structure optimised to minimise parasitic scattering. The system was benchmarked using standard paramagnetic reference samples, demonstrating EPR sensitivity comparable to commercial laboratory instruments. This work establishes a new class of multimodal instrumentation, enabling operando investigations of materials in which coupled spinlattice phenomena govern functionality, including batteries, catalysts, and quantum materials.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"625-640"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11511456","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828958","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":"Reply to “Comments on ‘Experimental Evaluation of Relationship Between Radiofrequency Heating Near Implanted Conductive Devices, Scanner-Reported B1+rms, and Transmit Power’”","authors":"David H. Gultekin;J. Thomas Vaughan;Devashish Shrivastava","doi":"10.1109/JMW.2026.3666608","DOIUrl":"https://doi.org/10.1109/JMW.2026.3666608","url":null,"abstract":"We describe the relationship between the RF-induced temperature change in a conductive metallic implant during the MRI, B_1+rms, and RF power for RF pulse sequences, RF coils, and Tx/Rx combinations. We show that both temperature and RF power change with RF pulse sequences, RF coils, and Tx/Rx combinations, whereas B_1+rms changes only with RF pulse sequences but not RF coils and Tx/Rx combinations. As a result, induced heating is associated with RF power propagation and loss corresponding to the B_1+rms.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"491-492"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11437567","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148505991","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":"50 GHz Piezoelectric Acoustic Filter","authors":"Omar Barrera;Jack Kramer;Lezli Matto;Vakhtang Chulukhadze;Sinwoo Cho;Michael Evan Liao;Mark S. Goorsky;Ruochen Lu","doi":"10.1109/JMW.2026.3661341","DOIUrl":"https://doi.org/10.1109/JMW.2026.3661341","url":null,"abstract":"This paper presents significant frequency scaling of acoustic filter technology to 50 GHz. This achievement is enabled by the periodically poled piezoelectric film LiNbO₃ multilayer stack, in which piezoelectric thin-films of alternating orientations are transferred in sequence, thereby allowing efficient exploitation of high-order modes with high quality factor and coupling coefficient in a thicker piezoelectric stack. The demonstrated filter is comprised of twelfth-order symmetric mode lateral-field-excited bulk acoustic wave resonators (XBARs), built on a 4-layer periodically poled piezoelectric 128° Y-cut lithium niobate (LiNbO₃) stack. The filter exhibits 3.3 dB insertion loss and a fractional bandwidth of 2.9% . The miniature design, with a footprint of 0.36 mm², makes it promising for future wireless front-end applications. These results represent the highest frequency acoustic filters reported to date, setting a new benchmark in piezoelectric filter technology. Upon further development, the platform could enable filters further into the FR2 range, essential for next-generation communication systems.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"391-400"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11408630","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148509099","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.2026.3662930","DOIUrl":"https://doi.org/10.1109/JMW.2026.3662930","url":null,"abstract":"","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"C2-C2"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11437566","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148509329","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":"Unified RF Module With Multiband Antenna and Electromagnetic Interference Suppression for Wi-Fi 7 Laptop Applications","authors":"Yu-Kai Huang;Chung-En Wu;Kuan-Hsueh Tseng;Yen-Sheng Chen","doi":"10.1109/JMW.2026.3674173","DOIUrl":"https://doi.org/10.1109/JMW.2026.3674173","url":null,"abstract":"Electromagnetic interference (EMI) from high-speed digital subsystems in laptops can couple into wireless front ends, particularly at 2.4 GHz, degrading link reliability and throughput. This work presents a unified hardware platform that combines EMI suppression and multiband antenna functions within a compact form factor. The system integrates a tri-band planar inverted-F antenna (PIFA), covering all Wi-Fi 7 bands (2.400–2.4835, 5.150–5.825, and 5.925–7.125 GHz), with a 2.4 GHz resonant absorber on a shared ground plane. The 50 mm × 10 mm absorber array, optimized for near-fi eld dissipation, fits entirely within the existing antenna clearance region. Measurements show an average 18.1 dB EMI reduction compared with air or copper reference and 19 dB at 2.43 GHz relative to a standalone antenna, without affecting radiation characteristics. System-level over-the-air throughput tests further validate the improvement: at −66 dBm received power, the downlink and uplink rates increase by 122 % and 75 %, respectively, while smaller gains occur high signal-to-noise ratio conditions. These results demonstrate an EMI-aware microwave integration strategy that achieves both interference suppression and tri-band wireless operation using standard PCB processes, offering a practical pathway for high-throughput wireless subsystems in compact electronic platforms.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"711-724"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11457254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828921","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":"Introduction to the March 2026 Issue","authors":"Peter H. Siegel","doi":"10.1109/JMW.2026.3667535","DOIUrl":"https://doi.org/10.1109/JMW.2026.3667535","url":null,"abstract":"This month we bring you 16 research papers in our regular March issue plus 8 more contributions in our Special issue on Microwaves in Medicine and Biology. We also announce our 2024 Best Paper Prize winners, our 2025 Outstanding Reviewers, and our upcoming 75^th Anniversary of the MTT Society’s special issue entitled “Microwaves are Everywhere”. We also review our stats and refresh our Topic Editor bios.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"287-297"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11437559","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148508832","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}