{"title":"Synthesis of In-Line Fully Canonical Filters by Solving a Matrix Completion Problem Under AW Ladder Constraints","authors":"Joel Mesas;Jordi Verdú;Pedro de Paco","doi":"10.1109/LMWT.2025.3573897","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3573897","url":null,"abstract":"This work extends a matrix-based numerical methodology to cover fully canonical generalized Chevyshev (GC) transfer functions by reconfiguring canonical filter topologies into dangling inline structures, with a direct impact on the consideration of ladder circuit filters. The transformation matrix that maps a canonical matrix to the dangling inline is defined in such a way that, within a mathematical matrix completion framework, it can nullify the source-load coupling, modify the source and load reactances to accommodate the phase at the first and last extracted-pole sections of the network, and capture the response information in a different size matrix.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1272-1275"},"PeriodicalIF":3.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11030593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078593","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}
Ze Du;Zhi-Yu Duan;Ke Zhan;Zhen-Hua Wu;Ji-Sheng Chen;Hu Li;Ming-Zhou Zhan
{"title":"A Large Chip-Width TMICs Packaging Solution for THz Applications","authors":"Ze Du;Zhi-Yu Duan;Ke Zhan;Zhen-Hua Wu;Ji-Sheng Chen;Hu Li;Ming-Zhou Zhan","doi":"10.1109/LMWT.2025.3575467","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3575467","url":null,"abstract":"In this letter, a large chip-width terahertz monolithic integrated circuits (TMICs) packaging solution at terahertz (THz) frequencies is presented. The proposed electromagnetic bandgap (EBG) structure in this design can effectively suppress various interference modes generated when the slit width increases. The mode conversion and interconnection between coplanar waveguide with ground (CPWG) and waveguide are realized using integrated on-chip dipole antenna transition model. To verify the proposed solution, a packaging structure accommodating a chip width of 3760 <inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m and an on-chip integrated dipole antenna transition model were designed and fabricated. The test results show that in the frequency range of 214–242 GHz, the return loss is better than 9 dB and the insertion loss is better than 4 dB, the de-embedded average loss is less than 1 dB.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1440-1443"},"PeriodicalIF":3.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xingyue Guo;He Ming Yao;Yuan’an Liu;Michael Ng;Shiji Song
{"title":"Deep Learning Approach for Microwave Imaging in Broad Frequency Band Based on Physics-Driven Loss and Deep Convolutional V-Net Structure","authors":"Xingyue Guo;He Ming Yao;Yuan’an Liu;Michael Ng;Shiji Song","doi":"10.1109/LMWT.2025.3575160","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3575160","url":null,"abstract":"This article proposes a novel deep learning (DL) approach to realize quantitative real-time microwave imaging (MWI) in the extremely broad frequency band. The proposed DL approach is based on the deep convolutional V-net structure, which employs the residual block and deep convolutional operation to improve its generality and performance. To integrate the physics-based prior to DL model, the inverse-forward closed-loop training framework is introduced to compute the training loss, which comprises two fundamental components: 1) the inverse process for computing data-driven loss, which directly quantifies the dissimilarity between the predictions of our proposed V-net and the actual target contrasts and 2) the forward process for computing physics-driven loss, which evaluates the distinctions between the input EM scattered field and the computed EM scattered field derived from the prediction of V-net. Consequently, the proposed DL method can work with excellent accuracy even for heterogeneous and high-contrast targets, only requiring the single-frequency far-field-measured EM scattered field at the arbitrary frequency in the extremely broad frequency band. Moreover, the proposed DL method can present satisfactory robust on the extremely broad frequency band and provide nearly the same excellent inversion performance on totally different frequencies for one target scatterer. Numerical benchmarks illustrate the feasibility of this proposed DL method.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1264-1267"},"PeriodicalIF":3.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"General Method for Characterizing Switchable Elements for RIS Using De-Embedding Structures","authors":"Mehmet Emin Arslan;Ulrich Nordmeyer;Niels Neumann","doi":"10.1109/LMWT.2025.3574501","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3574501","url":null,"abstract":"Reconfigurable intelligent surfaces (RISs) play a significant role in 6G wireless communications by dynamically controlling the reflections of electromagnetic (EM) waves. In this work, p-i-n diodes are used to achieve the necessary phase shifts in the 1-bit RIS unit cells. In order to characterize these diodes over a frequency range from 10 to 30 GHz, de-embedding structures are carefully designed and analytically modeled. By de-embedding the test structure and matching the model parameters with empirical measurements, the behavior of p-i-n diodes within RIS unit cells is accurately determined. The developed characterization method can be easily adapted to other RF measurement tasks involving complex designs at high frequencies, thus broadening its applicability.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1444-1447"},"PeriodicalIF":3.4,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fachun He;Shuang Liu;Longfang Ye;Huali Zhu;Dan Lei;Jun Yan
{"title":"Multipassband and Wide-Stopband Filters via Independent Tuning of High-Order SSPP Modes","authors":"Fachun He;Shuang Liu;Longfang Ye;Huali Zhu;Dan Lei;Jun Yan","doi":"10.1109/LMWT.2025.3575715","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3575715","url":null,"abstract":"We propose a novel <italic>F</i>-fold spoof surface plasmon polaritons (SSPPs) unit with independently tunable high-order rejection bands. The dispersion characteristics of the proposed <italic>F</i>-fold SSPPs are analyzed. The results show that the cutoff frequencies of Modes 2 and 3 can be precisely adjusted through structural parameters, enabling independent control of the stopband position formed by these two modes, without affecting the fundamental mode (Mode 0) or Mode 1. Therefore, the passband number, bandwidth, and stopband width can be flexibly manipulated for the design of multiple passband filters. For verification, a tri-passband, quad-passband filter, and wide stopband filter are designed, fabricated, and measured. The wide stopband filter achieves a 547% increase in the stopband width compared to the tri-passband filter. Good agreement between the simulations and measurements confirms the feasibility of the proposed structure and design method.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1288-1291"},"PeriodicalIF":3.4,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li Qian;Liyu Zhu;Jun Xu;Weiheng Chen;Zhiqiang Yu;Jianyi Zhou;Wei Hong
{"title":"Manufacture-Friendly Millimeter-Wave Filter Based on Double-Folded SIW Resonators","authors":"Li Qian;Liyu Zhu;Jun Xu;Weiheng Chen;Zhiqiang Yu;Jianyi Zhou;Wei Hong","doi":"10.1109/LMWT.2025.3565314","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3565314","url":null,"abstract":"This letter proposes manufacture-friendly millimeter-wave (mm-Wave) bandpass filter (BPF) based on double-folded substrate integrated waveguide (DFSIW) cavities. Using an incompletely folded structure and parallel rectangular slots as coupling structures, the BPF achieves reduced insertion loss (IL) and enhanced robustness against processing errors. Furthermore, the compact space between adjacent folded slots was transformed into a cross-coupling structure, which significantly improves frequency selectivity without introducing additional radiation loss. In addition, high-quality (<italic>Q</i>) factor layer stacking is implemented to further minimize IL. A <italic>Ka</i>-band filter prototype based on the multilayer printed circuit board (PCB) is fabricated and measured to confirm the feasibility.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1296-1299"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Novel Low-Profile Lossy Transmission Line Planar Matched Load for System Integration","authors":"Lijuan Zhu;Kaijun Song;Yong Fan","doi":"10.1109/LMWT.2025.3572592","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3572592","url":null,"abstract":"A novel low-profile lossy transmission line planar matched load for system integration is proposed. To achieve wider bandwidth and optimize space utilization, the proposed matched load is realized using a high-order lossy interdigital filter consisting of lossy transmission lines with high loss tangent. The matched load function is ultimately achieved through energy dissipation during the transmission. With the assistance of artificial intelligence (AI) optimization technology, accurate multi-complex parameter optimization is realized. A low-profile planar matched load using a high-order lossy interdigital filter with dimensions of only <inline-formula> <tex-math>$1.59times 0.3times 0.02~lambda g$ </tex-math></inline-formula> is fabricated and tested. The input return loss bandwidths of 20 dB are in the range of 6.7–9.65 GHz, with a relative bandwidth of 36.1%.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1336-1339"},"PeriodicalIF":3.4,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liang Kong;Shiyuan Li;Baojiang Yan;Kebin Liu;Chi Zhang;Yuyue Zhou;Chong He
{"title":"Enhancing Dynamic Range of Complex-Ratio Estimation Between Two RF Signals With Time Modulation","authors":"Liang Kong;Shiyuan Li;Baojiang Yan;Kebin Liu;Chi Zhang;Yuyue Zhou;Chong He","doi":"10.1109/LMWT.2025.3574212","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3574212","url":null,"abstract":"A novel method for extending the dynamic range of complex-ratio measurement between two radio frequency (RF) signals is proposed. It relies on adjusting the proportion of the signals in the combined one. By using a single-pole double-throw (SPDT) switch to periodically modulate the two RF signals and analyzing the spectrum of the combined signal, the amplitude ratio and phase difference can be determined. Measurement errors mainly stem from switch isolation limits and strong-to-weak signal interference, and the latter can be mitigated by proportion adjustment. Compared to previous works, the proposed method achieves an improved dynamic range and higher precision while preserving the low complexity of single-channel receiver. A 200 MHz–2 GHz measurement system is built, achieving 65 dB and 360° dynamic ranges with low root mean square errors (RMSEs). Experimental results match the measurements from the vector network analyzer (VNA), validating the effectiveness of the proposed method.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1436-1439"},"PeriodicalIF":3.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shivakumar Chedurupalli;Lalitha Saripaka;Abhilash Thumiki;K. C. James Raju
{"title":"Highly Selective Compact Cascaded Suspended Stripline Bandpass Filter","authors":"Shivakumar Chedurupalli;Lalitha Saripaka;Abhilash Thumiki;K. C. James Raju","doi":"10.1109/LMWT.2025.3571941","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3571941","url":null,"abstract":"This letter presents a novel compact, highly selective, wideband (WB) bandpass filter (BPF) based on the suspended substrate stripline (SSS) technique, realized by cascading a low pass filter (LPF) and a high pass filter (HPF) for <inline-formula> <tex-math>$K_{u}$ </tex-math></inline-formula>-band applications. To enhance compactness without compromising the filter specifications, the longest stubs in the layout were minimized to their shortest feasible lengths. The filter operates within a passband of 13–14.8 GHz, achieving a fractional bandwidth of 13%. Schematic and electromagnetic (EM) simulations were conducted using the Advanced Design System (ADS) software, and the corresponding layout sections were fabricated on a 5-mil RT/Duroid 5880 substrate, which has a compact footprint of <inline-formula> <tex-math>$2.7times 1.4$ </tex-math></inline-formula> cm<sup>2</sup>. The scattering parameter responses of the fabricated filter were measured, demonstrating an insertion loss (IL) of 1.5 dB within the passband and a return loss (RL) of approximately 15 dB. Furthermore, the design achieves a sharp rejection greater than 60 dB at a frequency offset of 4% from the band edges and maintains a wide stopband extending up to 24 GHz with a minimum rejection of 30 dB.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1276-1279"},"PeriodicalIF":3.4,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Carbon Nanotube Schottky Diode With Broadband Nonlinear Equivalent Circuit Model for Millimeter-Wave Frequency Multiplication","authors":"Murong Zhuo;Hongrong Qiu;Simin He;Li Ding;Zhiyong Zhang;Defu Wang;Lian-Mao Peng","doi":"10.1109/LMWT.2025.3574378","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3574378","url":null,"abstract":"This letter presents a nonlinear model for carbon nanotube (CNT) Schottky diodes, integrating dc, small-signal, and large-signal parameters. A broadband equivalent model, spanning dc to 110 GHz, is proposed to meet the frequency requirements for millimeter-wave (mm-wave) frequency multiplication. A CNT Schottky diode with a 100-nm channel length was designed, fabricated, and measured, demonstrating good agreement with the model. The diode exhibited a maximum current of −7.7 mA, a cutoff frequency exceeding 180 GHz, and a conversion loss of 24 dB at 60 GHz with an input power of 13 dBm at 30 GHz. To the best of the authors’ knowledge, this is the first demonstration of CNT-based Schottky diodes for millimeter-wave frequency multiplication, supported by the model.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1372-1375"},"PeriodicalIF":3.4,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}