IEEE journal of microwaves最新文献

{"title":"Non-Contact Probing of Active Semiconductor Devices Using Terahertz Waves","authors":"Bryce Chung;Harrison Lees;Jeffrey L. Hesler;Chitchanok Chuengsatiansup;Withawat Withayachumnankul","doi":"10.1109/JMW.2026.3653411","DOIUrl":"https://doi.org/10.1109/JMW.2026.3653411","url":null,"abstract":"Terahertz waves are sensitive to changes in free carriers within semiconductor materials. To date, research in this area has focused on spectroscopic analysis of exposed wafers and inactive devices. In principle, terahertz waves should be able to probe packaged and active semiconductor devices subjected to bias signals, which induce changes in the carrier density across a PN junction. A challenge lies in a discrepancy between the probing spot size on the order of millimeters at 275 GHz, and the sub-wavelength footprint of a PN junction, which results in small changes of any reflected terahertz waves. Although normally buried underneath the phase noise of the terahertz oscillator, these minuscule changes in carrier density can be observed as a baseband signal in complex reflection measurements using a homodyne quadrature receiver. Due to the high sensitivity of this transceiver, sub-wavelength targets can be effectively monitored with conventional terahertz optics. These experimental results demonstrate the ability of terahertz waves to non-invasively monitor semiconductor device activity. We anticipate that this work will be a precursor for non-destructive inspection of chips during production and the covert monitoring of operational devices.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"324-333"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11437556","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148508833","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":"Uncertainty Propagation in GaN HEMT Small-Signal Models for Millimeter-Wave Circuit Design Applications","authors":"Jason Shell;Edward Gebara;Nicholas C. Miller","doi":"10.1109/JMW.2026.3664760","DOIUrl":"https://doi.org/10.1109/JMW.2026.3664760","url":null,"abstract":"This paper investigates the impact of S-parameter measurement uncertainties on broadband modeling and circuit design using gallium nitride (GaN) high electron mobility transistors (HEMTs) from 0.5–110 GHz. A process for creating a small-signal model (SSM) for the GaN device is described, as well as a method for propagating uncertainties through SSM simulations. This work identifies two salient SSM parameters to which uncertainties can be applied to replicate the trends in the measurement uncertainties. A comparison of the propagated uncertainties in the measurement and the model data is analyzed. Two matching network circuits were designed utilizing the SSM, and the effect of uncertainties on these circuit designs is discussed. These results indicate that measurement uncertainty has a notable impact on <inline-formula><tex-math>$S_{11}$</tex-math></inline-formula> and <inline-formula><tex-math>$S_{22}$</tex-math></inline-formula> in both conjugate match network designs and specified gain network designs, with more variation present in conjugate match designs. From these results, we conclude that there is an inverse relationship between the amount of mismatch in RF matching network circuit designs and the impact of uncertainties on their input and output matching conditions. Even in circuits designed for no mismatch, there is still a noticeable variation in S-parameters, particularly in the phase of <inline-formula><tex-math>$S_{22}$</tex-math></inline-formula>. The findings of this investigation could be useful for RF engineers to better understand uncertainties in measurements and extracted models, as well as integrated circuit designs that utilize them.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"418-428"},"PeriodicalIF":4.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11417816","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148510661","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 May 2026 Issue","authors":"Peter H. Siegel","doi":"10.1109/JMW.2026.3687885","DOIUrl":"https://doi.org/10.1109/JMW.2026.3687885","url":null,"abstract":"This month we bring you 13 research papers on a wide range of topics, from near field coupled leaky wave lenses for material characterization, to crystallography studies based on electron paramagnetic resonance spectroscopy, to mapping the variations in conductivity of brain tumors, to low loss THz filters, and more. We also review our performance statistics and remind readers to visit us at our booth at the IEEE International Microwave Symposium this coming June 9^th.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"603-614"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11513289","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828955","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 Special Issue","authors":"J.-C. Chiao;Sandra Costanzo;Changjun Liu;Peter H. Siegel","doi":"10.1109/JMW.2026.3669712","DOIUrl":"https://doi.org/10.1109/JMW.2026.3669712","url":null,"abstract":"Microwaves have been applied to medical and biological applications since the earliest days of power generation and propagation. Since health is a very personal issue, impacting all of our lives, it is both appropriate and advantageous to stay up to date with the latest developments and tools that may have a direct bearing on our well being. Progress, especially in the development of electromagnetic analysis tools focused on biological platforms, has been rapid and significant. Enhancements to diagnosis and treatment can make broad and notable benefits to healthcare systems, with substantial financial and societal impacts. With these thoughts in mind, we bring you this special issue of <sc>IEEE Journal of Microwaves</small> that is focused on recent advances for applications in medicine and biology.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"498-501"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11455392","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557589","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":"Wireless Power Transfer-Enabled Optogenetic Stimulation of Hypoglossal Motoneurons in Mice for Functional Studies in Obstructive Sleep Apnea","authors":"Giacomo Paolini;Giulia Battistini;Elisa Augello;Stefano Bastianini;Chiara Berteotti;Dario Coraci;Viviana Lo Martire;Diego Masotti;Elena Miglioranza;Simone Trovarello;Emilia Volino;Giovanna Zoccoli;Alessandra Costanzo","doi":"10.1109/JMW.2025.3642178","DOIUrl":"https://doi.org/10.1109/JMW.2025.3642178","url":null,"abstract":"Obstructive sleep apnea (OSA) is a widespread sleep-related breathing disorder linked to cardiovascular and cognitive complications. Although continuous positive airway pressure (CPAP) remains the standard therapy, poor patient adherence limits its effectiveness. Hypoglossal nerve stimulation is a promising alternative, and optogenetic activation offers superior spatiotemporal precision. However, before clinical use, this approach requires thorough validation in animal models using platforms that preserve natural behavior. This work proposes a fully wireless alternative to conventional optogenetic platforms which rely on tethered optical fibers, restricting the animal's mobility, inducing tissue inflammation, and limiting experimental flexibility. Fully implantable, miniaturized systems with wireless power transfer (WPT) and control capabilities address the need for reduced invasiveness, enabling natural behavior and long-term studies. We present the design and the in vivo validation of a battery-free, wireless optogenetic platform for in vivo studies on small laboratory mice, designed to minimize device size, weight, and invasiveness. A conformal WPT system of inductive resonant transmitting coils at 13.56 MHz is proposed to be integrated into the laboratory cage hosting the mice. A miniaturized, lightweight, and flexible receiving system (weighing less than 0.6 g) is designed to be implanted on the back of the mouse in a saddle-like configuration. The implanted device hosts the rectification circuitry, used to drive a microscale light-emitting diode (LED) positioned over the hypoglossal nuclei. In this way, optogenetic stimulation without fiber-optic tethers is obtained. Full-wave electromagnetic simulations and experimental validation are first carried out to assess the WPT link performance, demonstrating high tolerance to relative translational and angular displacement between the transmitting and receiving coils, and stable harvested power across the cage volume. For a transmitted power of 1.5 W, a minimum DC power of 20 mW has been obtained in the worst-case position of the mouse inside the cage, sufficient for the LED operation. Finally, in vivo experiments are presented, confirming not only the LED activation but also the hypoglossal nerve stimulation, fully compliant with the radiant flux requirements for optogenetic neurostimulation under realistic conditions. These results demonstrate the feasibility and robustness of the proposed WPT system for untethered, battery-free optogenetic stimulation in lightweight murine models with OSA, providing a platform for preclinical neuroscience research, paving the way toward next-generation low-invasiveness neuromodulation strategies.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"561-573"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11320310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557870","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 Journal of Microwaves Table of Contents","authors":"","doi":"10.1109/JMW.2026.3662936","DOIUrl":"https://doi.org/10.1109/JMW.2026.3662936","url":null,"abstract":"","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"C4-C4"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11437561","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557938","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.2026.3666598","DOIUrl":"https://doi.org/10.1109/JMW.2026.3666598","url":null,"abstract":"","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"C2-C2"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11455413","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557972","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":"Design of Near-Field Coupled Leaky-Wave Lens Antennas With Flat Interfaces for Material Characterization at Sub-THz Frequencies","authors":"Nick van Rooijen;Maria Alonso-delPino;Nuria Llombart","doi":"10.1109/JMW.2026.3668936","DOIUrl":"https://doi.org/10.1109/JMW.2026.3668936","url":null,"abstract":"This work describes the design of sub-Terahertz lens antennas that are coupled in the near field. The lenses have a flat interface, making them suitable for material characterization under plane wave incidence. A waveguide-based leaky-wave antenna feed illuminates the lenses efficiently with a Gaussian pattern over a bandwidth of 140 to 220 GHz. Then, a large permittivity hyperboloid lens converts the feed pattern into a plane wave with high Gaussicity. The use of dense dielectric materials significantly reduces field spreading effects when compared to setups with free-space propagation. Furthermore, the final lens architecture presents a flat interface, enabling direct lens-to-lens coupling for 2-port measurements with only −3 dB of coupling loss. This way, a quasi-optical Thru-Reflect-Line calibration can be performed, thereby making accurate extraction of material properties via full S-parameter matrix possible. Two materials were studied with this technique in a full-wave simulation, showcasing errors below 1 percent for permittivity and 2 percent for loss tangent, using a standard plane-wave propagation model.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 3","pages":"615-624"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11430532","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828976","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-Efficiency Inductive Antenna System With a Magnetic Focusing Unit and a Matching Module for Wireless Hyperthermia: Design and Verification","authors":"Shasha Ren;Jincheng Zou;Aili Zhang","doi":"10.1109/JMW.2025.3629108","DOIUrl":"https://doi.org/10.1109/JMW.2025.3629108","url":null,"abstract":"Wireless power transfer (WPT) has emerged as a transformative technology for applications ranging from biomedical implants to remote sensing. However, conventional WPT systems face limitations in power transfer efficiency, and particularly a significant attenuation occurs when high-frequency powers penetrate dense media like biological tissue. This work introduces a high-efficiency antenna system designed for wireless hyperthermia in peripheral arteries, which demonstrates enhanced penetration capability through biological tissues, making it ideal for powering deep-tissue medical implants with medium power (from 1w to 100w). The innovative antenna system comprises a coil, an external ferrite-based magnetic focusing unit (MFU), and an impedance matching module. The optimized leakage-shaped MFU was simulated and found to result in 2.1∼6.6× increase in magnetic field strength. The measured port gain of our antenna system, which reflects the efficiency of WPT, increases by 7.7∼14 dBm compared to the conventional coil antenna. Moreover, the receiver was powered with still 95% of maximum voltage despite a 30° angular deviation, showing adaptability to misalignments. The integrated matching module achieves impedance transformation to 50 Ω at 1.5 MHz. After matching, the reflection coefficient S₁₁ of the antenna is −30 dBm and the port gain rises up by 32 dBm. In the heating test, a 40% increase in heating rate is achieved. Power transfer efficiency (PTE) is 33-25% and heating efficiency (HE) is 4.6-3.1 °C/W through a 1.5–2.5 cm phantom thickness. The demonstrated enhancement of the proposed antenna system suggests it to be a promising method for in-vivo deep (a few centimeters) wireless hyperthermia treatment.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"550-560"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11271150","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557820","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":"Dynamic Range Limitations of a Microwave Imaging Setup for Breast Cancer Detection","authors":"Martin Maier;Micha Schernus;Joerg Schoebel;Vadim Issakov","doi":"10.1109/JMW.2025.3641181","DOIUrl":"https://doi.org/10.1109/JMW.2025.3641181","url":null,"abstract":"There are multiple microwave breast imaging (MBI) systems that are already conducting clinical trials. One common feature of these systems is the use of expensive radio-frequency (RF) laboratory equipment, such as vector network analyzers (VNA). To replace the VNA in an MBI setup with a significantly more cost-effective radar system, it is necessary to derive suitable hardware specifications. A fundamental parameter is the dynamic range, defined as the ratio of the maximum to the minimum usable signal power. A modern VNA can support a dynamic range of more than 120 dB. However, it might not be necessary for the radar system to match the VNA's dynamic range specifications. This is because the MBI setup itself affects the usable dynamic range. In this work, we investigate how much the usable dynamic range of an MBI setup is limited by clutter and noise. For this purpose, we utilize a frequency-modulated continuous-wave (FMCW) radar system operating from 6–14 GHz. Our results demonstrate the need to analyze the entire imaging setup rather than a single component to define the appropriate hardware parameters.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"6 2","pages":"588-600"},"PeriodicalIF":4.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11311552","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557937","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}