IEEE Transactions on Microwave Theory and Techniques最新文献_第8页

Time-Periodic Transmission Lines on Finite Intervals: A Hybrid Sturm--Liouville--Floquet Formulation 有限区间上的时间周期传输线：一个混合Sturm- Liouville- Floquet公式

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-08-05 DOI: 10.1109/TMTT.2026.3717614

Giulio Antonini;Daniele Romano

{"title":"Time-Periodic Transmission Lines on Finite Intervals: A Hybrid Sturm--Liouville--Floquet Formulation","authors":"Giulio Antonini;Daniele Romano","doi":"10.1109/TMTT.2026.3717614","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3717614","url":null,"abstract":"This article presents a unified and rigorous framework for the analysis of finite-length transmission lines whose per-unit-length (PUL) parameters vary periodically in time. The spatial dependence is treated through a Sturm–Liouville (SL) modal decomposition that enforces exact terminal boundary conditions on a finite interval, while temporal periodicity is handled by a Floquet–harmonic-balance formulation based on block Toeplitz convolutions. The resulting frequency-domain description provides a structured hybrid modal–Floquet operator that generalizes the classical pole–residue expansion of the linear time invariant (LTI) case. In parallel, we derive a closed time-periodic state-space model for the truncated modal system and its Floquet-lifted counterpart for periodic steady-state analysis. The formulation incorporates the parametric terms <inline-formula> <tex-math>$dot {L}(t)$ </tex-math></inline-formula> and <inline-formula> <tex-math>$dot {C}(t)$ </tex-math></inline-formula> in a transparent way and provides a structured framework for the inclusion of nonlinear terminations through dedicated trace and injection operators. The resulting model supports transient simulation, energy accounting, and periodic steady-state analysis, while also providing a basis for future extensions to more general nonlinear configurations. The approach recovers the classical LTI theory exactly and offers a continuous-space counterpart to unit-cell periodic models of modulated structures.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"7935-7952"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11642620","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928282","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}

引用次数: 0

A Group Theory-Based Numerical Mode Matching Method for Layered Waveguides With Discrete Symmetry 基于群理论的离散对称分层波导数值模式匹配方法

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-07-16 DOI: 10.1109/TMTT.2026.3711171

Taihe Li;Zefei Sun;Ke Chen;Han Lin;Jie Liu;Qing Huo Liu

{"title":"A Group Theory-Based Numerical Mode Matching Method for Layered Waveguides With Discrete Symmetry","authors":"Taihe Li;Zefei Sun;Ke Chen;Han Lin;Jie Liu;Qing Huo Liu","doi":"10.1109/TMTT.2026.3711171","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3711171","url":null,"abstract":"Accurate analysis of layered waveguides is crucial for microwave device design. Numerical mode matching (NMM) is a widely adopted technique for such problems. As a semi-analytical approach, NMM inherently features dimensionality-reduction characteristics as it reduces a 3-D waveguide discontinuity problem into a series of 2-D problems. However, when applied to spatially symmetric waveguides, the conventional NMM suffers from computational redundancy and requires complex calibration procedures to properly resolve degenerate modes. Since waveguide symmetry is the primary cause of mode degeneracy, it frequently leads to ambiguity and errors during mode classification. To address these challenges, a group theory-based NMM (GT-NMM) method is proposed. By employing symmetry operators, the electromagnetic field is decomposed into independent subspaces, ensuring precise identification of all modes. The proposed method maintains the same accuracy as conventional NMM while significantly enhancing computational efficiency. Finally, four numerical examples are presented to validate the efficiency and accuracy of GT-NMM.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"8001-8015"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928283","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}

引用次数: 0

High-Coupling Tunable Acoustic Resonators in Monolithic Barium Titanate 单片钛酸钡的高耦合可调谐声学谐振器

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-08-06 DOI: 10.1109/TMTT.2026.3716563

Ian Anderson;Agham Posadas;Alexander A. Demkov;Ruochen Lu

{"title":"High-Coupling Tunable Acoustic Resonators in Monolithic Barium Titanate","authors":"Ian Anderson;Agham Posadas;Alexander A. Demkov;Ruochen Lu","doi":"10.1109/TMTT.2026.3716563","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3716563","url":null,"abstract":"The growing number of wireless communication bands has driven demand for compact, low-loss, and frequency-adjustable radio frequency (RF) filtering. Tunable acoustic resonators are well-suited to address these needs, offering a path toward reconfigurable front ends with reduced component count. In this work, we extend our previous conference results to investigate epitaxial barium titanate (BTO) grown on silicon as a platform for tunable acoustic resonators. We demonstrate lateral excitation of symmetric Lamb (S0) modes in 120-nm X-cut BTO membranes using a multicell electrode architecture that simultaneously achieves high electromechanical coupling and practical impedance levels. Devices are fabricated with laterally patterned electrodes on released BTO membranes. Under an applied DC bias, ferroelectric domains align, allowing electrical excitation, frequency tuning, and quality-factor enhancement of acoustic modes. The primary resonance near 700-MHz exhibits a Bode quality factor of 173, electromechanical coupling of up to 24.5%, and series and parallel resonance tunability of 2.3% and 5.6%, respectively, with the parallel tuning reflecting the transition from the unpoled to the fully poled state. Voltage-dependent material parameters, including permittivity, stiffness, and piezoelectric coefficients, are back-fit through a combination of a modified Butterworth–Van Dyke model and finite-element simulation to explain the observed trends. These results highlight monolithic BTO on silicon as a promising material system for laterally excited, tunable acoustic resonators for reconfigurable RF applications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"8332-8342"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928312","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}

引用次数: 0

A 26--28 GHz Quadrature-Phase Load-Modulated Balanced Amplifier With Inherent Gain Compression Elimination 具有固有增益压缩消除的26—28 GHz正交相位负载调制平衡放大器

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-07-14 DOI: 10.1109/TMTT.2026.3711938

Haoyang Jia;Ruijia Liu;Lin Qi;Anding Zhu

{"title":"A 26--28 GHz Quadrature-Phase Load-Modulated Balanced Amplifier With Inherent Gain Compression Elimination","authors":"Haoyang Jia;Ruijia Liu;Lin Qi;Anding Zhu","doi":"10.1109/TMTT.2026.3711938","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3711938","url":null,"abstract":"Load-modulated balanced amplifiers (LMBAs) offer compelling efficiency advantages over broad frequency ranges, but their inherent gain compression in the power back-off (PBO) region poses a significant linearity challenge for modern 5G millimeter-wave applications where digital predistortion (DPD) is difficult to deploy. This article presents a quadrature-phase LMBA (QLMBA) that addresses this limitation through a quadrature-phase control signal injection technique. By establishing a 90° phase offset between the balanced amplifier (BA) and control amplifier (CA), the proposed architecture isolates BA and CA power contributions, suppressing the nonlinear gain compression inherent to conventional LMBA designs. A theoretical analysis demonstrates that, with a properly selected CA to BA drive ratio, gain compression can be fully eliminated. Additionally, a reactive compensation network is integrated into the BA output matching network (OMN) to mitigate the imaginary admittance variation introduced by quadrature load modulation (QLM), improving back-off efficiency. A proof-of-concept 26–28 GHz QLMBA fabricated in a 0.12-<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m gallium nitride (GaN) HEMT process achieves saturated output power of 32.3 dBm, drain efficiency of 29.3% at peak and 20.71% at 6-dB PBO at 27 GHz, with less than 1 dB gain compression across the full power range. When driven by 100/400 MHz 5G New Radio (NR) frequency range 2 (FR2) 64 QAM signals, the QLMBA achieves an adjacent channel leakage ratio (ACLR) of −34.2/−30.6 dBc and an error vector magnitude (EVM) of 4.5%/5.5% without DPD, demonstrating its suitability for next-generation millimeter-wave transmitters.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"8130-8140"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11610586","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928323","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}

引用次数: 0

Nonlinear Characterization of Thin-Film LiNbO3 Acoustic Filters 薄膜LiNbO3声滤波器的非线性特性

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-07-17 DOI: 10.1109/TMTT.2026.3710507

Omar Barrera;Bryan T. Bosworth;Taran Anusorn;Kenny Huynh;Ian Anderson;Nicholas R. Jungwirth;Michael Liao;Sinwoo Cho;Jack Kramer;Lezli Matto;Mark S. Goorsky;Nathan D. Orloff;Ruochen Lu

{"title":"Nonlinear Characterization of Thin-Film LiNbO3 Acoustic Filters","authors":"Omar Barrera;Bryan T. Bosworth;Taran Anusorn;Kenny Huynh;Ian Anderson;Nicholas R. Jungwirth;Michael Liao;Sinwoo Cho;Jack Kramer;Lezli Matto;Mark S. Goorsky;Nathan D. Orloff;Ruochen Lu","doi":"10.1109/TMTT.2026.3710507","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3710507","url":null,"abstract":"Compact, high-performance components in millimeter-wave (mmWave) communication systems demand new acoustic filter technology at increasingly higher frequencies. Among various promising mmWave platforms, first-order antisymmetric (A1) mode laterally excited bulk acoustic resonators (XBARs) in thin-film lithium niobate (LiNbO3) have perhaps the most impressive linear performance. Despite these advances, there are few reports of nonlinear characterization of LiNbO3 filters at mmWaves. Here, we address this gap by developing a new nonlinear methodology for high-frequency filters. The result is a methodology for performing power-dependent S-parameters and third-order intermodulation (IMD3) measurements. To test our methodology, we fabricated filters on transferred single-crystal LiNbO3 films on sapphire (Al2O3) and silicon (Si) substrates with an amorphous silicon (aSi) sacrificial layer. At 21.8 GHz, the filters on Al2O3 demonstrated an insertion loss (IL) of 1.48 dB, a 3 dB fractional bandwidth (FBW) of 17.7%, and in-band third-order input intercept points (IIP3) of 50.8 dBm. At 21.6 GHz, the filters on silicon demonstrated an IL of 2.47 dB, a 3 dB FBW of 18.6%, and an in-band IIP3 of 46.5 dBm. The nonlinear results conclusively show that thermal stability and passband distortion improved on the Al2O3 substrate, confirming that substrate selection plays a pivotal role in mitigating nonlinearity in acoustic front-end modules.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"7807-7817"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928324","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}

引用次数: 0

A Spectrally Optimized Tetrahedral Operator Paradigm for Electromagnetic--Thermal--Mechanical Analysis of High-Power Microwave Devices 高功率微波器件电磁-热-力学分析的光谱优化四面体算子范式

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-08-11 DOI: 10.1109/TMTT.2026.3719438

Huan Wang;Naixing Feng

{"title":"A Spectrally Optimized Tetrahedral Operator Paradigm for Electromagnetic--Thermal--Mechanical Analysis of High-Power Microwave Devices","authors":"Huan Wang;Naixing Feng","doi":"10.1109/TMTT.2026.3719438","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3719438","url":null,"abstract":"High-power microwave devices involve strong electromagnetic (EM) losses, thermal accumulation, and structural deformation, rendering multiphysics simulation indispensable for reliable design. However, for microwave components with intricate geometries, conventional full-wave solvers remain constrained in reconciling geometric flexibility, high-order accuracy, and computational efficiency. In this work, we propose a spectrally optimized-tetrahedral operator paradigm (SO-TOP) that enables full-wave EM–thermal–mechanical analysis within a unified unstructured framework. The EM response is modeled using a high-order hierarchical vector finite element operator, while the transient thermal and mechanical fields are discretized by an orthogonal tetrahedral spectral element operator constructed via collapsed-coordinate transformation. Combined with the precomputed Vandermonde matrices, our proposed method enables high-order accurate integration and efficient matrix assembly, yielding strongly diagonal-dominant mass matrices and improved conditioning for implicit time integration. Numerical results demonstrate close agreement with COMSOL Multiphysics while delivering notable gains in computational efficiency. The proposed SO-TOP framework offers a scalable and high-fidelity tool for multiphysics simulation of high-power microwave devices.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"7790-7806"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928326","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}

引用次数: 0

Flip-Chip Integration of Millimeter-Wave LNA Based on Rectangular Microcoaxial Transmission Line 基于矩形微同轴传输线的毫米波LNA倒装集成

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-08-21 DOI: 10.1109/TMTT.2026.3719084

Lifang Zhao;Kaixue Ma;Yongqiang Wang;Ningning Yan

{"title":"Flip-Chip Integration of Millimeter-Wave LNA Based on Rectangular Microcoaxial Transmission Line","authors":"Lifang Zhao;Kaixue Ma;Yongqiang Wang;Ningning Yan","doi":"10.1109/TMTT.2026.3719084","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3719084","url":null,"abstract":"To address the high-frequency integration requirements of a millimeter-wave low-noise amplifier (LNA), through 3-D electromagnetic simulation optimization, equivalent circuit modeling, noise cascading, and microwave link budget analysis, the Ka-band LNA flip-chip integration based on a rectangular microcoaxial transmission line (R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL) vertical transition structure is implemented for the first time using flip-chip technology. Testing results of the R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL exhibit an insertion loss (IL) better than −1.12 dB and a return loss (RL) superior to −13.84 dB across the 40-GHz band. The integrated module exhibits a noise figure (NF) of 3.47–4.31 dB; the gain reaches 17–21 dB in the main band of 32–36 GHz and rolls off to 12.77–15.70 dB at 37–38 GHz, with an RL better than −10-dB over most of the band. No significant performance degradation is observed after three reflow cycle tests. Owing to inherent passive losses and high-frequency parasitics, there is a slight noise degradation, but this low-cost flip-chip scheme satisfies practical millimeter-wave engineering requirements with outstanding thermal cycling reliability. It provides new approaches and technical support for the high-frequency integration of millimeter-wave LNA chips and 3-D heterogeneous integration of multi-MMIC systems at elevated frequencies.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"7903-7909"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148924074","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}

引用次数: 0

Synthesis of Continuously Tunable Diplexers With Decoupling Network 用解耦网络合成连续可调谐双工器

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-07-27 DOI: 10.1109/TMTT.2026.3714112

Peng Zhang;Huijin Huang;Guoqun Cao;Beizun Liu;Yi Zeng;Ming Yu

{"title":"Synthesis of Continuously Tunable Diplexers With Decoupling Network","authors":"Peng Zhang;Huijin Huang;Guoqun Cao;Beizun Liu;Yi Zeng;Ming Yu","doi":"10.1109/TMTT.2026.3714112","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3714112","url":null,"abstract":"This article proposes a synthesis method for continuously tunable diplexers based on an all-resonator decoupling topology. In coupled-resonator diplexers, strong interchannel interference often leads to severe passband distortion, making independent channel frequency tuning highly challenging. To overcome this limitation without resorting to complex external matching or power-distribution networks, a decoupling strategy is introduced by incorporating proper cross-couplings between channels. Based on a three-port network admittance analysis, mathematical conditions for effectively eliminating interchannel interference are derived. The diplexer synthesis process with these conditions imposed is detailed, guiding the design of diplexers with decoupled channels. To validate the proposed method, this article presents the synthesis examples of the diplexers with and without transmission zero, as well as with asymmetric topologies. Additionally, a continuously tunable diplexer prototype is designed and fabricated. Experimental results demonstrate that, while the Rx channel is fixed, the Tx channel achieves wide-range continuous and independent frequency tuning. Moreover, the Tx band can be contiguous with the Rx band. Throughout the tuning process, the return losses within the Rx and Tx passbands are well maintained, thereby validating the effectiveness of the proposed decoupling strategy.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"8307-8318"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148925455","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}

引用次数: 0

Cell-Free Coherent Joint Transmission for 6G ISAC Enabled by Microwave Photonic Synchronization 微波光子同步实现6G ISAC无细胞相干联合传输

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-08-12 DOI: 10.1109/TMTT.2026.3720258

Zhijian Zhang;Haoran Wu;Lihan Wang;Jiangtao Zhang;Xudong Wen;Peidong Feng;Jianbo Sun;Xiaowei Ma;Mingyu Liu;Wancheng Yang;Xiangchuan Wang;Shilong Pan

{"title":"Cell-Free Coherent Joint Transmission for 6G ISAC Enabled by Microwave Photonic Synchronization","authors":"Zhijian Zhang;Haoran Wu;Lihan Wang;Jiangtao Zhang;Xudong Wen;Peidong Feng;Jianbo Sun;Xiaowei Ma;Mingyu Liu;Wancheng Yang;Xiangchuan Wang;Shilong Pan","doi":"10.1109/TMTT.2026.3720258","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3720258","url":null,"abstract":"Distributed cell-free communication networks can synthesize ultralarge virtual apertures and provide substantial distributed gains for 6G communication systems. However, multinode spatial coherence remains limited by the complexity of conventional fiber-based synchronization networks. In this article, a scalable and architecturally streamlined microwave photonic synchronization scheme capable of the concurrent distribution of time-triggered, local oscillator (LO), and clock signals over optical fiber is proposed. By exploiting the inherent properties of these signals for real-time delay metrology and active link compensation, the proposed approach circumvents the need for auxiliary optical wavelengths or additional hardware overhead in the fronthaul network. The experiments show a delay measurement deviation of ±1.5 ps, and phase stabilization within ±2.5°@10 GHz is achieved over a 2-km fronthaul link. We further present, to the best of the authors’ knowledge, the first distributed coherent integrated sensing and communication (ISAC) cell-free network enabled by microwave photonic synchronization. With two remote nodes (RNs), the cell-free networks yield an over 5.3 dB improvement in error vector magnitude (EVM) and sensing signal-to-noise ratio (SNR) based on the coherent gain. The proposed architecture provides a practical route toward scalable coherent ISAC networks with enhanced coverage and capacity.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"8395-8402"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148925485","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}

引用次数: 0

Efficient RIS Inverse Design Enabled by Microwave Network Decoupling and Active Learning 基于微波网络解耦和主动学习的RIS高效逆设计

IF 5.2 1区工程技术

IEEE Transactions on Microwave Theory and Techniques Pub Date : 2026-09-01 Epub Date: 2026-08-17 DOI: 10.1109/TMTT.2026.3722227

Yan Liu;Weihang Yu;Jiaming Wei;Ximei Zhao

{"title":"Efficient RIS Inverse Design Enabled by Microwave Network Decoupling and Active Learning","authors":"Yan Liu;Weihang Yu;Jiaming Wei;Ximei Zhao","doi":"10.1109/TMTT.2026.3722227","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3722227","url":null,"abstract":"Reconfigurable intelligent surfaces (RISs) are promising for dynamic wireless networks, yet their inverse design is still limited by costly full-wave datasets and inefficient optimization in high-dimensional topology spaces. To address these challenges, this article proposes a physics-informed and data-efficient inverse design framework. First, a surrogate model combining microwave-network cascading theory with a residual convolutional neural network (CNN) forward predictor is developed. The network predicts the S-parameters of passive RIS topologies, which are then cascaded with diode equivalent impedances to obtain reflection coefficients, enabling rapid prediction for different diode models or bias states without retraining. To reduce data acquisition cost, a query-by-committee (QBC) active learning strategy is introduced to iteratively select high-uncertainty samples for full-wave simulation, reducing the required training data by about 60% while maintaining comparable accuracy. Based on this surrogate, a hierarchical topology optimization method combines nonuniform rational B-spline (NURBS)-based global skeleton search with pixel-level simulated-annealing refinement, preserving structural connectivity while retaining local design freedom. The framework is validated through a 5-GHz 1-bit RIS and a 5.8-GHz 2-bit near-field focusing RIS, demonstrating its efficiency and reliability for rapid reconfigurable RIS design.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 9","pages":"7982-8000"},"PeriodicalIF":5.2,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926177","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}

引用次数: 0