IEEE Transactions on Microwave Theory and Techniques最新文献

{"title":"Dual-Polarized Millimeter-Wave Handset Phased Array With Digital Predistortion Achieved by Compact Hole-Coupling Feedback Architecture","authors":"Ren-Rong Zhao;Yucheng Yu;Fan Wu;Debin Hou;Peng Chen;Chao Yu","doi":"10.1109/TMTT.2026.3727266","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3727266","url":null,"abstract":"This article proposes a dual-polarized millimetre-wave phased array integrated with a compact hole-coupling feedback (FB) structure to support online digital predistortion (DPD) for handset applications. The integrated hole-coupling structure can capture the distortion signals of the power amplifiers (PAs) as the FB signal. Since the FB structure is integrated in the antenna element, the need for an additional coupling structure is eliminated, enhancing the compactness of the array. Using a single-pole four-throw (SP4T) switch (SW), the FB signal can be captured by the time-shared scheme without interruption of the signal transmission, enabling online updating. Measurement results show that the proposed FB structure has negligible impact on the radiation performance of the antenna. The radiation pattern of the phased array can scan from −45° to +45°. The DPD performance is validated using a 100-MHz 256-QAM 5G NR signal at a carrier frequency of 26 GHz. The measurement results show that the error vector magnitude (EVM) is reduced to below 3.5%, while the adjacent channel leakage ratio (ACLR) is improved to below −40 dBc, achieving performance comparable to that of conventional over-the-air (OTA) DPD across various steering angles.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 10","pages":"9237-9250"},"PeriodicalIF":5.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiport Analytical Pixel Electromagnetic Simulator (MAPES) for AI-Assisted Microwave Circuit and RFIC Design","authors":"Junhui Rao;Yi Liu;Jichen Zhang;Zhaoyang Ming;Tianrui Qiao;Yujie Zhang;Chi Yuk Chiu;Hua Wang;Ross Murch","doi":"10.1109/TMTT.2026.3723770","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3723770","url":null,"abstract":"This article proposes a novel analytical framework, denoted the multiport analytical pixel electromagnetic simulator (MAPES). MAPES enables efficient and accurate prediction of the electromagnetic (EM) performance of arbitrary pixel-based microwave (MW) and radio frequency integrated circuit (RFIC) structures. Unlike the internal multiport method (IMPM), which optimizes only connecting elements within a fixed, gap-separated pixel skeleton, MAPES operates directly on the all-pixel presence/absence formulation used in recent MW/RFIC design. This is enabled by diagonal virtual pixels, an occupancy-to-load mapping, and a multilayer/via port-level formulation that have no counterpart in IMPM. By introducing virtual pixels and diagonal virtual pixels and inserting virtual ports at critical positions, MAPES captures all horizontal, vertical, and diagonal EM couplings within a single multiport impedance matrix. Only a small set of full-wave simulations (typically about 1% of the datasets required by artificial intelligence (AI)-assisted EM emulators) is needed to construct this matrix. Subsequently, any arbitrary pixel configuration can be evaluated analytically using a closed-form multiport relation without additional full-wave calculations. The proposed approach eliminates data-driven overfitting and ensures accurate results across all design variations. Using MAPES, comprehensive examples for single- and double-layer printed circuit boards (PCBs) and complementary metal–oxide–semiconductor (CMOS) processes (180 and 65 nm) confirm that high prediction accuracy with 600–<inline-formula> <tex-math>$2000times $ </tex-math></inline-formula> speed improvement is achieved compared to full-wave simulations. Owing to its efficiency, scalability, and reliability, MAPES provides a practical and versatile tool for AI-assisted MW circuit and RFIC design across diverse fabrication technologies.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 10","pages":"8692-8705"},"PeriodicalIF":5.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11665549","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From Fixed to Arbitrary Frequency: A Scalable LLM-Enhanced Framework for Electromagnetic Device Design","authors":"Zhiyin Jin;Jin Jia;Peng Wang;Zhenning Li;Gert Frølund Pedersen;Ming Shen;Tao Hong;Wen Jiang","doi":"10.1109/TMTT.2026.3728789","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3728789","url":null,"abstract":"Conventional electromagnetic (EM) design is typically restricted to predefined frequency ranges. This article presents a language-driven generative framework for high-fidelity EM synthesis at arbitrary frequencies, incorporating physics-scaling-guided surrogate model (PSGSM) with vector to interval line preprocessing (VILP) and variable-controlled data collection (VCDC). The approach is defined by three methodological pillars. First, frequency scaling invariance is leveraged to decouple multiband responses into a normalized domain, enabling robust cross-frequency data/model reuse. Second, the VILP method transforms stochastic user vectors into structured, piecewise linear intervals, allowing the surrogate model to perceive continuous scaling trajectories rather than isolated points. Third, the VCDC strategy stabilizes the low-frequency resonance (<inline-formula> <tex-math>$f_{1}$ </tex-math></inline-formula>) to isolate high-frequency variations (<inline-formula> <tex-math>$f_{2}$ </tex-math></inline-formula>), ensuring data alignment with scaling logic and significantly enhancing sampling efficiency. The framework is validated through the design of a bandpass filter (BPF) and dual-passband frequency-selective surfaces (DP-FSSs). Experimental results from a fabricated DP-FSS prototype demonstrate high precision and flexibility in frequency-independent EM synthesis.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 10","pages":"8779-8795"},"PeriodicalIF":5.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Realization of Arbitrary Phase Difference and Slope With High Linearity for Millimeter-Wave Coupler Based on Modified VPSs","authors":"Yu Fei Pan;Hui Hai Peng;Ye Yang;Shao Yong Zheng","doi":"10.1109/TMTT.2026.3728106","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3728106","url":null,"abstract":"Previous works concerning phase-shifting components usually concentrated on the phase-shifting ranges or phase difference values at the center frequency. Seldom have works mentioned the manipulation of phase difference slope (PDS) and its linearity within a certain frequency bandwidth, especially in the millimeter-wave (mmW) band. In this article, a universal design method for realization of arbitrary phase difference and PDS in mmW couplers is proposed. Two modified via-pad-slot (MVPS) structures constructed by vertically/horizontally connecting two rows of original via-pad-slots (VPSs) by slots are introduced. The vertically/horizontally connected VPS (VCVPS/HCVPS) can effectively change the phase slope of the substrate-integrated-waveguide (SIW) transition without influencing the match. By combining different quantities of MVPSs and original VPSs in the SIW coupler, arbitrary phase difference and PDS can be realized. Equivalent circuits and field distributions of the MVPSs are provided to illustrate the working principle. For demonstration, four −45° couplers and four −120° couplers operating at 30 GHz with four different PDS values are designed, fabricated, and measured. The results show that arbitrary PDS and high slope linearity are realized, validating the effectiveness of the proposed methodology.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 10","pages":"8989-9003"},"PeriodicalIF":5.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automated Broadband Power Amplifier Design via Circuit-Graph Evolution and Layout-Aware Synthesis","authors":"Yuxuan Chen;Hang Yu;Zi Jun Su;Slim Boumaiza","doi":"10.1109/TMTT.2026.3724479","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3724479","url":null,"abstract":"This article presents an automated design framework for broadband power amplifiers (PAs) based on a graph-driven evolutionary optimization approach. In the proposed framework, the input and output matching networks are represented as graphs and jointly synthesized in both the topology and parameter spaces to optimize the small- and large-signal performance of the PA. This approach enables the automated synthesis of physically realizable broadband source and load impedance trajectories without relying on predefined circuit templates. In addition, a graph-to-layout generation methodology is introduced to automatically translate the evolved circuit graphs into manufacturable layouts while incorporating electromagnetic (EM)-aware optimization. The proposed framework is experimentally validated through the design and fabrication of a 10-W GaN PA operating from 3.2 to 4.3 GHz and supporting 1 GHz instantaneous modulation bandwidth across the 5G NR n77 band. The fabricated prototype achieves a peak output power of 41.6  ± 0.8 dBm and a peak power-added efficiency (PAE) ranging from 40% to 63% across the operating band. Under excitation with a 1 GHz 5G NR 256-QAM OFDM signal exhibiting a 9-dB peak-to-average power ratio (PAPR), the PA achieves an adjacent channel power ratio (ACPR) of −52.7 dBc and an error vector magnitude (EVM) of 0.66% after digital predistortion (DPD) using a complexity-reduced Volterra-series model.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 10","pages":"8861-8876"},"PeriodicalIF":5.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis Design of Narrowband High-Order All-Pole Optimum Bandstop 3-D FSS Based on Slotline Resonators and Transformers","authors":"Wanping Zhang;Zheng Ping;Bo Li;Yumei Chang;Lei Zhu","doi":"10.1109/TMTT.2026.3728437","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3728437","url":null,"abstract":"This article proposes a synthesis method for high-order bandstop frequency-selective surfaces (FSSs) by mapping with a fully distributed transmission-line (TL) equivalent circuit model (ECM). To address free-space filtering impedance constraints, a novel design concept integrating multisection Chebyshev impedance matching transformers and series short-circuited stub-loaded bandstop networks is proposed and validated, thus forming a low-characteristic-impedance hybrid bandstop network. First, equating the transformer reflection coefficient to the Chebyshev polynomials yields synthesized multisection transformers with an alternative matching performance. Similarly, solving the polynomial coefficient equations for the optimum transfer function and the series stub-loaded bandstop network enables efficient synthesis of arbitrary-order all-pole optimum bandstop filtering responses with designated 3-dB stopband bandwidth and remarkable out-of-band transmission near the stopband. Then, main and terminally enclosed slotlines are quantitatively mapped to the main TLs and series stubs via parametric extraction, thereby completing the design procedure. Finally, a dual-polarized second-order 3-D FSS (4/6 GHz center frequencies, 12% bandwidth) and a single-polarized third-order 3-D FSS (5-GHz center frequency, 18% bandwidth) are theoretically synthesized, full-wave simulated, and experimentally measured based on a free-space measurement method. Measured results show stable bandstop filtering responses over incident angles from 0° to 45°, consistent with theory and simulations, thereby verifying the accuracy of the proposed synthesis approach and its effectiveness in efficiently designing bandstop FSS with a prescribed narrowband high-order spatial filtering response.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 10","pages":"8631-8643"},"PeriodicalIF":5.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Substrate-Integrated Waveguide Dual-Band Bandpass Filter and Diplexers With Large Frequency Ratios","authors":"Zhenghai Luo;Kang Zhou","doi":"10.1109/TMTT.2026.3729832","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3729832","url":null,"abstract":"This article provides a novel design methodology for a substrate-integrated waveguide (SIW) dual-band bandpass filter (DBBPF) and a diplexer with large frequency ratios (FRs). First, an aperture-coupling topology is employed to route the low-frequency (LF) and high-frequency (HF) signals into dedicated LF and HF SIW elements, respectively. This enables each passband or channel to be independently controlled with good impedance matching. Second, to suppress undesired harmonics between interbands or interchannels, a novel miniaturized SIW bandpass filter (BPF) with an out-of-band rejection exceeding <inline-formula> <tex-math>$17boldsymbol {f}_{mathbf {0}}$ </tex-math></inline-formula> (<inline-formula> <tex-math>$boldsymbol {f}_{mathbf {0}}$ </tex-math></inline-formula> is the operating frequency of the BPF) is proposed based on quarter-mode SIW (QMSIW) resonant cavities. Underlying the proposed design methodology, SIW DBBPFs with an FR exceeding 5 as well as diplexers with an arbitrary FR in the range of (0, 17] can be readily realized. Generally, typical design strategies for large-FR devices are limited by narrow operating frequency ranges. By contrast, SIW components based on the proposed method can realize a dramatically wider frequency span, capable of spanning the microwave and millimeter-wave bands. Finally, three large-FR SIW components are designed, fabricated, and measured to validate the proposed method.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 10","pages":"9100-9111"},"PeriodicalIF":5.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149222621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-Fidelity-Guided High-Fidelity Bayesian Optimization for High-Speed Link Signal Integrity","authors":"Xiao-Yang Wu;Da-Wei Wang;Wen-Sheng Zhao","doi":"10.1109/TMTT.2026.3718457","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3718457","url":null,"abstract":"To address the tradeoff between the high computational cost of high-fidelity simulations and the limited reliability of machine learning (ML) models in high-speed link signal integrity (SI) optimization, this article proposes a low-fidelity-guided high-fidelity Bayesian optimization (LFGHF-BO) method. Within the conventional Bayesian optimization (BO) framework, low-fidelity information is incorporated as auxiliary guidance, and the predictive distribution is reconstructed to improve sampling decisions, thereby enhancing optimization efficiency while preserving the dominance of high-fidelity evaluations. Unlike conventional approaches, the low-fidelity model is not directly involved in modeling the objective function but instead provides trend information to guide the search process, reducing the dependence on prediction accuracy. Moreover, under the practical assumption that historical high-fidelity simulation data are available, the low-fidelity model can be trained using historical data from simple structures and then reused for optimization tasks involving more complex structures, which effectively reduces the additional modeling cost. Numerical results demonstrate that, under a limited high-fidelity evaluation budget, the proposed method significantly improves sampling efficiency and accelerates convergence while maintaining optimization reliability.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"7886-7902"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148924073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3-D Printed Narrowband Sub-THz Filter With a Wide Spurious-Free Window Using High-Q Spherical TE101 Resonators","authors":"Lu Qian;Yongxin Cheng;Carl Leonard;Hussein Ezzeddine;Bertrand Thomas;Simon Rea;Peter G. Huggard;Yi Wang","doi":"10.1109/TMTT.2026.3712466","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3712466","url":null,"abstract":"A narrowband subterahertz (sub-THz) bandpass filter with a wide spurious-free stopband, fabricated using high-precision 3-D printing technology, is presented. The filter is based on high-<inline-formula> <tex-math>$Q$ </tex-math></inline-formula> spherical TE₁₀₁-mode resonators, whose inherently high unloaded quality factor enables the realization of low loss over very narrow bandwidth. To suppress out-of-band spurious resonances, a combination of a meandered filter topology and cutoff waveguide sections is employed. To address the manufacturing challenges associated with curved spherical geometries, projection micro-stereolithography (P<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>SL) 3-D printing is adopted together with an adaptive slicing strategy. As a proof-of-concept, an eighth-order filter with a center frequency of 180 GHz and a bandwidth of 5 GHz (2.8%) is designed, fabricated, and measured. Mechanical characterization confirms excellent dimensional accuracy and surface quality. RF experimental results show a minimum measured insertion loss of 0.7 dB and a worst-case in-band return loss better than 15 dB. The extracted unloaded quality factor is approximately 3600, which is the highest value reported to date for bandpass filters operating in this frequency range.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"8297-8306"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inline Rectangular Micro-Coaxial Line Bandpass Filters With Novel Mixed-Coupling Structure for Ka-Band SatCom Application","authors":"Jia-Hao Su;Jin Xu;Xiao Li;Yan-Sen Zhao;Zhi-Qiang Zhou;Jia-Hao Zhao","doi":"10.1109/TMTT.2026.3719650","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3719650","url":null,"abstract":"This article presents inline Ka-band rectangular micro-coaxial line (R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL) bandpass filters (BPFs) with mixed-coupling, fabricated using the micro-structure electrochemical fabrication (MEFAB) process. A novel mixed-coupling structure based on a pair of fully coupled grounded half-wavelength stepped-impedance resonators (GHSIRs) is proposed for designing R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL BPFs, which is particularly advantageous for the MEFAB process. By controlling the middle section of the structure between two coupling GHSIRs, the mixed-coupling polarity can be flexibly tuned to be either electric-dominant or magnetic-dominant, producing transmission zeros (TZs) at the lower or upper stopband, respectively. The TZ generation and control of the two proposed mixed-coupling structures are analyzed in detail and verified experimentally with two second-order R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL BPF designs. To verify the scalability of this design method, two fourth-order and one seventh-order R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL BPFs operating in the same 30–31 GHz range are further designed based on the proposed structures, and then fabricated and measured. In addition, to mitigate probe-to-probe coupling that prevents accurate out-of-band suppression characterization in on-chip probe measurement, a low-cost surface-mount technology (SMT) measurement method using isolation blocks (IsoBlks) is presented. Despite the narrowband operation, these three mixed-coupling R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL BPFs still feature low insertion loss (IL), controllable TZs, compact size, and a quasi-planar structure, showing promising potential for Ka-band SatCom applications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"8343-8354"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}