IEEE journal of microwaves最新文献

{"title":"Integrated Self-Contained Trajectory Estimation and Multistatic SAR Imaging in a Non-Static Uncoupled Bistatic Radar Network","authors":"Patrick Fenske;Tobias Koegel;Roghayeh Ghasemi;Danielle Gunders-Hunt;Martin Vossiek","doi":"10.1109/JMW.2025.3554050","DOIUrl":"https://doi.org/10.1109/JMW.2025.3554050","url":null,"abstract":"Radar imaging performance can be significantly improved by creating synthetic apertures along a radar sensor's trajectory compared to standard MIMO imaging radars. Additionally, observing the scenery from both monostatic and bistatic perspectives with large bistatic angles can further increase the information content of radar images, as different parts of complex targets can exhibit different scattering mechanisms. Both technologies, synthetic aperture radar and coherent multistatic radar networks, come with demanding system requirements regarding the localization and synchronization of the involved radars, which are addressed by the proposed approach. The unique aspect of our novel bi-/multistatic radar approach is that no auxiliary sensor technology is needed to determine the trajectory. The same radar signals are jointly used at the same time for trajectory determination, clock synchronization, and bistatic SAR imaging. The integrated self-contained trajectory estimation is based on a particle filter algorithm that processes the line-of-sight radar signals of the bistatic radar pairs, which are exchanged in a double-sided two-way ranging manner. This approach opens up new applications of bi-/multistatic radar for autonomous air and ground vehicles. However, the requirement of a line-of-sight connection between the radar pairs imposes a constraint on possible bistatic constellations and trajectories. Therefore, it is shown that suitable compromises regarding the geometry, localization accuracy, and resolution of SAR imaging must also be taken into account. We demonstrate the capabilities of this approach by generating monostatic and bistatic SAR images with 77 GHz SIMO FMCW radar sensors from indoor and outdoor measurement scenarios with synthetically generated apertures estimated by the integrated self-contained localization algorithm.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"600-615"},"PeriodicalIF":6.9,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10965474","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925042","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 Evaluation of Relationship Between Radiofrequency Heating Near Implanted Conductive Devices, Scanner-Reported B1+rms, and Transmit Power","authors":"David H. Gultekin;John T. Vaughan;Devashish Shrivastava","doi":"10.1109/JMW.2025.3550087","DOIUrl":"https://doi.org/10.1109/JMW.2025.3550087","url":null,"abstract":"Time-varying radiofrequency (RF) fields necessary to perform magnetic resonance imaging (MRI) may induce excessive heating near implanted conductive medical devices during MRI. The time and space-averaged root-mean-square effective magnetic field (B_1+rms) and specific absorption rate (SAR) have been proposed as metrics to control the RF-induced heating and avoid unintended thermal injury. We experimentally evaluate the relationship between the RF-induced heating near an implanted conductive medical device, scanner-reported B_1+rms, and RF power. RF heating was measured near the electrodes of a commercial deep brain stimulation (DBS) lead placed in a tissue-equivalent gel phantom using fluoroptic temperature probes in a commercial 3T scanner during MRI. Four RF transmit/receive coil combinations were used: a circularly polarized head transmit/receive coil, a 20-channel head/neck, a 32-channel head, or a 64-channel head/neck receive-only coil with a whole-body transmit coil. RF heating was induced by a 2D GRE sequence using two RF pulse types (fast and normal), three flip angles (30°, 60°, and 90°), and turning the receive-only coils off/on. The scanner-reported B_1+rms and RF power were recorded. Measurements show that temperature change correlates linearly with both RF power and square of B_1+rms for each coil and combination. However, the variation in heating for various RF coils and combinations was much larger for B_1+rms compared to RF power. Additional studies across other MR scanners are needed to better understand the extent of variation in RF-induced heating near implanted conductive devices as a function of scanner-reported B_1+rms and RF power to develop conservative and reliable patient labeling.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"518-525"},"PeriodicalIF":6.9,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10963882","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925335","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 Fully Integrated 0.48 THz FMCW Radar Sensor in a SiGe Technology","authors":"Florian Vogelsang;Jonathan Bott;David Starke;Marc Hamme;Benedikt Sievert;Holger Rücker;Nils Pohl","doi":"10.1109/JMW.2025.3553681","DOIUrl":"https://doi.org/10.1109/JMW.2025.3553681","url":null,"abstract":"The THz gap has been a significant research objective for photonics and electronics for decades. This work introduces a fully integrated frequency modulated continuous wave (FMCW) radar sensor with a center frequency of 0.48 THz, realized in a silicon-germanium (SiGe) technology. The sensor consists of a THz MMIC integrated onto a front-end printed circuit board (PCB) with FR4 substrate used for frequency synthesis and IF signal amplification. A dielectric polytetrafluoroethylene (PTFE) lens is mounted above the MMIC to act as transmitter (Tx) and receiver (Rx) lens as well as a physical protection for the bond wires of the MMIC. A back-end PCB generates the supply voltages and control signals, and its analog-digital-converter (ADC) samples the IF signal. The whole sensor is just 4.9 cm by 4.3 cm in size and is cost-efficient due to its design with FR4 PCBs. The MMIC reaches an output power of up to <inline-formula><tex-math>$-9$</tex-math></inline-formula> dBm. In FMCW operation with the full sensor, a tuning range of 49 GHz is reached along an equivalent isotropic radiated power (EIRP) of up to 22 dBm. Distance measurements were successfully tested for distances of up to 5 m, and a radiation pattern is presented. In summary, this article demonstrates the potential of SiGe technology in the THz range for applications like localization, material characterization, and communication.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"572-582"},"PeriodicalIF":6.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10959113","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925222","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":"Field Trial of Cluster Target Detection by Broadband Microwave Photonic MIMO Radar","authors":"Yuewen Zhou;Fangzheng Zhang;Jiayuan Kong;Yihan Wang;Jinhu Li;Kunyang Chen;Guanqun Sun;Yuhui He;Shilong Pan","doi":"10.1109/JMW.2025.3553507","DOIUrl":"https://doi.org/10.1109/JMW.2025.3553507","url":null,"abstract":"Cluster target detection is challenging for traditional narrow-band radars. Microwave photonic multiple-input-multiple-output (MIMO) radar is an emerging technique for accurate cluster target detection, which enhances range and angular resolution via its large bandwidth and virtual aperture. Previous research on microwave photonic MIMO radars focuses on the effectiveness of photonics-based hardware, while its advantages for practical applications have not been effectively validated. This paper demonstrates a field trial of cluster target detection by a broadband microwave photonic MIMO radar having an 8×8 MIMO array and a bandwidth of 8 GHz per channel. Using a broadband digital beamforming algorithm that compensates for aperture fill time, precise target detection is achieved without beam squint and broadening problems. Meanwhile, grating lobes due to sparse array are well suppressed, which enables the improvement of angular resolution by using large-aperture sparse array. In the experiment, detections of a single drone and three densely distributed drones as a cluster are implemented respectively. By comparing the results of 50-MHz narrowband MIMO detection and 8-GHz full-band MIMO detection, the advantage of broadband microwave photonic MIMO radar is verified. For single drone detection, the range resolution and angular resolution are estimated to be 2.1 cm and 0.17°, respectively, and the grating lobes are well suppressed with peak-to-maximum grating-lobe ratio over 13.5 dB. When detecting three drones as a cluster, the individuals are precisely distinguished and located. The results validate that the microwave photonic MIMO radar has high-resolution detection capability superior to traditional narrow-band radars, and it provides an effective and practical solution for cluster target detection.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"631-639"},"PeriodicalIF":6.9,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10949595","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925266","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 Johnson Noise Thermometry for Passive Temperature Sensing","authors":"Jasmin Falconer;Geneva Ecola;Zerina Kapetanovic","doi":"10.1109/JMW.2025.3569638","DOIUrl":"https://doi.org/10.1109/JMW.2025.3569638","url":null,"abstract":"Johnson noise thermometers (JNTs) are a promising primary thermometer technology for harsh environments, including nuclear plants, industrial agriculture, and space. However, they are impractical to deploy at large scale in resource-constrained environments since they require a constant power supply. This paper presents the first analysis and demonstration of a <italic>wireless</i> Johnson noise thermometer (WJNT). It addresses the deployment concerns of JNTs by separating the sensor, a passive antenna, and conductor from the active reader circuitry used to measure temperature. This makes the sensor easily scalable, completely passive, and detectable by a disconnected mobile reader system. In addition, the sensor's conductor can be distanced from its antenna to allow for the sensing of temperatures not accessible to the reader. This paper theoretically derives the signal-to-noise ratio and sensitivity of a WJNT. A proof-of-concept system was designed and evaluated in lab and outdoors to demonstrate its feasibility and effectiveness for use in different applications. The sensitivity, at room temperature, of the prototyped WJNT was measured to be 0.43 to 1 K for integration times ranging from 100 to 10 s using a 20 MHz bandwidth at 965 MHz.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 4","pages":"829-840"},"PeriodicalIF":6.9,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11018425","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598072","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":"Optimal Adjacent Output Phase Difference Assignments in Generalized One-Dimensional Five-Beam Switching Matrices","authors":"Shengjia Wu;Jiro Hirokawa;Takashi Tomura;Nelson J. G. Fonseca","doi":"10.1109/JMW.2025.3550804","DOIUrl":"https://doi.org/10.1109/JMW.2025.3550804","url":null,"abstract":"This paper discusses the optimal assignment of phase differences between adjacent output ports in a recently proposed generalized one-dimensional orthogonal switching matrix with five beams by considering the RF performance of the compared matrices, including bandwidth of reflection coefficients, frequency dependence of adjacent output phase differences, etc. To demonstrate the advantages of the optimal assignment, the worst assignment is used for comparison. Both assignments use the same couplers but have different values of phase shift, so the beam directions determined by adjacent output phase differences are decided by the phase shifters. The best and worst assignments are identified using the absolute sum of phase differences with reference to a straight waveguide, defined as the difference between the transmission phase of a one-layer-length straight waveguide and the actual required values of one-layer-length phase shifters. The optimal assignment has the smallest absolute sum of phase differences, while the worst assignment has the largest value. This proposed assignment selection technique is general and suitable for matrices with a large component count, which prevents using full-wave analyses to identify preferred configurations. The two assignments are realized using post-wall waveguide technology and designed to operate over the frequency band from 20 GHz to 24 GHz, using PTFE substrates having a thickness of 3.2 mm and a dielectric constant of 2.17. Both matrices are simulated, manufactured and measured by adding transitions to input ports and output ports and connecting with standard waveguide WR42. Both simulated and measured results confirm that the assignment resulting in the smaller absolute sum of phase differences has better performance than the one with the largest sum in terms of transmission and reflection coefficients, phase differences between adjacent output ports, and array factor, confirming the selected metric as a good indicator of the performance of the generalized orthogonal switching matrix.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 3","pages":"654-665"},"PeriodicalIF":6.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10944527","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143925227","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":"Low Loss Quartz Multilayer Substrates and Substrate Integrated Two-Plane Hybrid Couplers Enabled by Copper Direct Bonding","authors":"Takashi Tomura;Jiro Hirokawa;Osamu Kagaya;Nobutaka Kidera;Daisuke Yamanaka;Hisaaki Furukawa;Katsuaki Miyatani","doi":"10.1109/JMW.2025.3566010","DOIUrl":"https://doi.org/10.1109/JMW.2025.3566010","url":null,"abstract":"This paper presents a fused silica glass (quartz) multi-layer substrate using the copper direct bonding method. A fabricated substrate-integrated-waveguide (SIW) based two-plane hybrid coupler composed of five quartz layers showed low loss characteristics at the 60 GHz band. Quartz has low loss characteristics even at higher frequency bands but suffers from the difficulty of multilayer. We propose a copper direct bonding method to realize low-loss multilayer quartz substrates and characterize straight SIW lines and the two-plane hybrid coupler composed of a five-quartz-layer substrate. The straight SIW line shows low loss characteristics of 0.013 dB/mm at most from 57 GHz to 64 GHz with estimated <inline-formula><tex-math>$epsilon _{r}=3.75$</tex-math></inline-formula> and <inline-formula><tex-math>$tan delta =0.00034$</tex-math></inline-formula> for the quartz and <inline-formula><tex-math>$sigma = 4.0times 10^{7}$</tex-math></inline-formula> S/m for the copper. The low insertion loss between an external waveguide and the SIW located in the inner quartz layer is confirmed as 0.12 dB at most, from 58 GHz to 63 GHz. The two-plane hybrid shows a low amplitude imbalance of 0.75 dB with a low insertion loss of 1.1 dB. These results strongly show that the quartz multi-layer substrate using the copper direct bonding method enables low-loss multilayer microwave components. Because this fabrication technique is scalable and the number of quartz layers can be increased, it can be applied to beam-switching circuits and feeding circuits with low loss and compact volume.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 4","pages":"1003-1014"},"PeriodicalIF":6.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11008625","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597924","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":"Fully Digital Phased Array Harmonic Radar for Detecting Concealed Electronic Devices","authors":"Wonryeol Lee;Taeyong Jeong;Daju Lee;Kyusik Woo;Kang-Yoon Lee;Chang-Ryul Yun;Chulhun Seo;Juntaek Oh;Keum Cheol Hwang;Sun K. Hong","doi":"10.1109/JMW.2025.3563527","DOIUrl":"https://doi.org/10.1109/JMW.2025.3563527","url":null,"abstract":"This paper presents the design and performance evaluation of a fully integrated digital phased array-based nonlinear radar system. The proposed system employs a bi-static structure, where the transmitter and receiver are physically separated. The transmitter operates at 3–3.2 GHz, while the receiver is designed to capture the second harmonic responses at 6–6.4 GHz. The system consists of 64 channels for both transmission and reception, enabling electronic beam steering through phase shift control. To enhance the beamforming accuracy, a novel transmitter calibration method utilizing an oscilloscope instead of a network analyzer was implemented. The method simplifies synchronization requirements while maintaining precise phase alignment. Performance evaluation of the radar system was conducted through experimental validation in both free-space and concealed conditions, using arbitrary commercial electronic devices as targets. The experimental validation results demonstrated an average range error of 32.3 cm with a range resolution of 37.5 cm. Additionally, multi-target detection was performed using beamforming techniques. In free-space conditions, the radar achieved accurate target localization with angular errors below 1°. In concealed conditions, nonlinear reflections introduced minor localization errors due to clutter. Despite these challenges, the system successfully detected multiple targets by employing a clustering method. To the best of our knowledge, the system presented here is the first demonstration of a fully integrated digital phased array-based nonlinear radar in the open literature.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 4","pages":"868-881"},"PeriodicalIF":6.9,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11006501","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598073","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":"Fast In-Phantom Absorbed Power Density Evaluation at mmWaves Based on Infrared Measurements","authors":"Massinissa Ziane;Artem Boriskin;Maxim Zhadobov","doi":"10.1109/JMW.2025.3539871","DOIUrl":"https://doi.org/10.1109/JMW.2025.3539871","url":null,"abstract":"This article introduces a novel method for fast measurement of the absorbed power density (APD) induced by an electromagnetic field (EMF) emmitting device operating near the human body at frequencies above 6 GHz, taking into account antenna/body interaction. The method employs an infrared (IR) thermography to remotely monitor the heat induced in a reflectivity-based skin equivalent phantom designed to reproduce the EMF scattering properties of human skin and the APD inside the human body. Such a phantom, implemented in the form of a thin planar solid dielectric structure, perturbs the device under test in a similar way as it would be perturbed by the presence of the human body, allowing the absorbed microwave energy to be effectively converted into an IR signal. The heat dynamics and the spatial temperature distribution on the phantom surface are measured by an IR camera and then converted to APD by postprocessing. To enhance the sensitivity of the method and to minimize the effect of heat conduction, spectral filtering is used. The proposed method is validated at 60 GHz using reference antennas (i.e. a cavity-fed dipole array and a pyramidal horn loaded with a slot array). The measured APD is compared with the reference APD simulated in human skin. The high accuracy and significant measurement time reduction, compared to conventional RF-based APD evaluation techniques, demonstrate a promising potential of the proposed IR-based method for fast EMF dosimetry and user exposure compliance testing of millimeter-wave (mmWave) 5 G and 6 G wireless devices.","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 2","pages":"269-280"},"PeriodicalIF":6.9,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10930962","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654889","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 Information","authors":"","doi":"10.1109/JMW.2025.3541900","DOIUrl":"https://doi.org/10.1109/JMW.2025.3541900","url":null,"abstract":"","PeriodicalId":93296,"journal":{"name":"IEEE journal of microwaves","volume":"5 2","pages":"C2-C2"},"PeriodicalIF":6.9,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10931044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655004","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}