IEEE Transactions on Microwave Theory and Techniques最新文献

{"title":"Coherent Dual-Band Dual-Chirp Microwave Waveform Generation Based on a Polarization-Multiplexed Optoelectronic Oscillator","authors":"Changlong Du;Mingzhen Liu;Li Yang;Ping Li;Liangzun Tang;Shifeng Liu;Shilong Pan","doi":"10.1109/TMTT.2025.3638010","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3638010","url":null,"abstract":"We propose and experimentally demonstrate a coherent dual-band dual-chirp microwave waveform generation scheme based on a polarization-multiplexed optoelectronic oscillator (OEO). A dual-polarization binary phase shift-keying (DP-BPSK) modulator is employed to construct orthogonal signal paths, with a dual-passband filter integrated into the OEO loop. Mutual injection locking enables stable dual-frequency oscillations with low phase noise and a high side-mode suppression ratio (SMSR). The generated dual-frequency signal serves as a local oscillator (LO) to modulate an externally injected baseband linear frequency-modulated (LFM) waveform, producing coherent dual-band dual-chirp LFM signals. The proof-of-concept experiments demonstrate waveform generation centered at 10 and 16 GHz with tunable bandwidths, duty cycles, and repetition periods. Compared to a free-running OEO, the proposed scheme improves the SMSR by 36 dB and enhances the signal-to-interference ratio (SIR) of the generated LFM signals by 31 dB. Furthermore, relative to direct waveform synthesis using an arbitrary waveform generator (AWG), it achieves a 29-dB SIR improvement and significantly reduces spectral linewidth. The output bandwidth can be flexibly extended up to 12 GHz by adjusting the baseband chirp, demonstrating high configurability and spectral scalability. Owing to its compact architecture, high coherence, and excellent spectral purity, the proposed approach is well suited for advanced radar systems requiring high resolution and robust interference suppression.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1852-1860"},"PeriodicalIF":4.5,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154407","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":"Real-Time High-Accuracy Digital Wireless Time, Frequency, and Phase Calibration for Coherent Distributed Antenna Arrays","authors":"Jason M. Merlo;Samuel Wagner;John B. Lancaster;Jeffrey A. Nanzer","doi":"10.1109/TMTT.2025.3639461","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3639461","url":null,"abstract":"This work presents a fully-digital high-accuracy real-time calibration procedure for frequency and time alignment of open-loop wirelessly coordinated coherent distributed antenna array (CDA) modems, enabling radio frequency (RF) phase coherence of spatially separated commercial off-the-shelf (COTS) software-defined radios (SDRs) without cables or external references such as the global navigation satellite system (GNSS). Building on previous work using high-accuracy spectrally-sparse time of arrival (ToA) waveforms and a multistep ToA refinement process, a high-accuracy two-way time transfer (TWTT)-based time–frequency coordination approach is demonstrated. Due to the two-way nature of the high-accuracy TWTT approach, the time and frequency estimates are Doppler and multipath tolerant, so long as the channel is reciprocal over the synchronization epoch. This technique is experimentally verified using COTS SDRs in a lab environment in static and dynamic scenarios and with significant multipath scatterers. Time, frequency, and phase stability were evaluated by beamforming over coaxial cables to an oscilloscope which achieved time and phase precisions of ~60–<inline-formula> <tex-math>$mathbf {mathrm {70~text {p}text {s} }}$ </tex-math></inline-formula>, with median coherent gains above 99% using optimized coordination parameters, and a beamforming frequency root-mean-square error (RMSE) of 3.73 ppb in a dynamic scenario. Finally, experiments were conducted to compare the performance of this technique with previous works using an analog continuous-wave two-tone (CWTT) frequency reference technique in both static and dynamic settings.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1962-1980"},"PeriodicalIF":4.5,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11301896","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154459","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":"Broadband Frequency Reconfigurable Resonator for Rydberg Atomic Enhancement Sensing","authors":"Kai Yang;Yi Lin;Zhanshan Sun;Yunqi Fu","doi":"10.1109/TMTT.2025.3635598","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3635598","url":null,"abstract":"Resonant structures provide a promising approach to significantly enhance the sensing sensitivity of Rydberg atomic receivers. However, conventional resonators predominantly operate at fixed frequencies, thereby constraining the intrinsic broadband response capabilities of Rydberg atoms. This study introduces a broadband frequency reconfigurable resonator (BFRR) engineered to augment sensitivity while preserving the broadband characteristics of atomic receivers. By employing varactor diodes to dynamically adjust equivalent capacitance and PIN diodes to selectively activate distinct inductive branches, the BFRR achieves continuous electronic tuning from 231 to 586 MHz, corresponding to a relative bandwidth of 86.9%. In <sc>off</small>-resonant atomic heterodyne configurations, the integration of the BFRR enhances sensitivity by nearly two orders of magnitude across the tuning range, attaining a sensitivity of 30.4 (nV/cm)/<inline-formula> <tex-math>$sqrt{text {H}z}$ </tex-math></inline-formula> at 564.2 MHz. This advancement significantly improves both the sensitivity and broadband adaptability of Rydberg atomic receivers, thereby offering essential support for progress in quantum electrometry.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1874-1882"},"PeriodicalIF":4.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154446","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":"Arbitrary Microwave Waveform Generation Based on Optical Domain Modulation","authors":"Jiaxue Feng;Congcong Liu;Nan Zhou;Yunping Bai;Ya Jin;Huashun Wen;Kunpeng Zhai;Jiazheng Sun;Edwin Yue Bun Pun;Sha Zhu;Ning Hua Zhu","doi":"10.1109/TMTT.2025.3631585","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3631585","url":null,"abstract":"Arbitrary microwave waveforms have become increasingly crucial for diverse applications, including high-capacity wireless communication, advanced radar systems, electronic countermeasures, and precision instrumentation. Generating arbitrary microwave waveforms with precise and flexible control over amplitude, phase, and frequency is critical to meet these applications’ stringent performance demands. In contrast to conventional electronic waveform generators, photonic generation methods overcome inherent limitations, offering substantial benefits like ultrabroad bandwidth, high-frequency operation, resistance to electromagnetic interference, and superior reconfigurability. This article reviews recent developments in photonic generation of arbitrary microwave waveforms, focusing on several prominent optical-domain techniques, including frequency-to-time mapping (FTTM), direct space-to-time mapping (DST), temporal pulse shaping (TPS), optical heterodyne technology, optical frequency combs (OFCs), optical injection, electro-optic modulation, and optoelectronic oscillation (OEO). We systematically analyzed the key characteristics, advantages, and application potential of these techniques, emphasizing recent research achievements and innovations. Moreover, photonic integration technology represents a pivotal step toward the practical arbitrary microwave waveforms generation. Integrated photonic microwave chips significantly reduce system size, weight, and power consumption, while enhancing stability and scalability. Such integrated systems are particularly promising for compact and portable arbitrary microwave waveforms generation in applications like on-chip radar, miniaturized communication modules, and flexible radio frequency (RF) testing platforms.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1812-1840"},"PeriodicalIF":4.5,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154468","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":"Real-Time Deployment of Pruned Unsupervised DNN for Blind Equalization in a Photonics-Aided W-Band Wireless System","authors":"Jie Zhang;Wen Zhou;Qihang Wang;Sheng Hu;Sicong Xu;Chengzhen Bian;Jingtao Ge;Jingwen Lin;Siqi Wang;Zhihang Ou;Tengsheng Zhang;Tong Wang;Jianjun Yu","doi":"10.1109/TMTT.2025.3636545","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3636545","url":null,"abstract":"The evolution beyond 5G and the advent of new 6G applications pose increasing challenges for communication in dense urban and hotspot areas. Photonics-assisted millimeter-wave (mm-Wave) communication systems have emerged as attractive solutions to meet these demands. Various enhancement schemes based on traditional digital signal processing (DSP) and neural networks have been proposed. However, the limitations of traditional DSP algorithms and the high complexity of supervised neural networks hinder real-time transmission. To address this issue, this article proposes an unsupervised DNN-based equalizer built upon the traditional constant modulus algorithm (CMA) for blind equalization of PAM signals, with structured pruning applied to facilitate practical deployment. Compared to the conventional CMA, the blind DNN equalizer effectively handles both linear and nonlinear impairments and achieves better bit error rate (BER) performance. Structured pruning reduces model floating-point operations (FLOPs) by 34%, successfully transforming the originally nondeployable architecture into a compact model executable in real-time on a field programmable gate array (FPGA), at the cost of a slight BER increase from <inline-formula> <tex-math>$3.53times 10^{-3}$ </tex-math></inline-formula> to <inline-formula> <tex-math>$6.84times 10^{-3}$ </tex-math></inline-formula>. We demonstrate a real-time photonics-assisted W-band wireless system based on an FPGA, employing the blind DNN equalizer to enhance performance. The system achieves real-time transmission of 14.7456-Gb/s PAM4 signals over a 200-m free-space link, attaining a BER of <inline-formula> <tex-math>$6.84times 10^{-3}$ </tex-math></inline-formula>. This work explores high-capacity real-time communication in dense AI environments and serves as a representative case of integrating traditional DSP algorithms with data-driven neural networks.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"1086-1097"},"PeriodicalIF":4.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049272","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":"Dual-Polarization and Dual-Beam EWG Leaky Wave Antenna for 2 × 2 MIMO Application","authors":"Longlong Lin;Xu Shi;Zongming Xu;Yichun Shen;Jian-Xin Chen","doi":"10.1109/TMTT.2025.3638239","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3638239","url":null,"abstract":"This article presents a novel dual-polarization and dual-beam elliptical waveguide (EWG) leaky wave antenna (LWA), which can be used in a <inline-formula> <tex-math>$2times 2$ </tex-math></inline-formula> multi-input multioutput (MIMO) system. The antenna works on two spatial harmonic waves (<inline-formula> <tex-math>$u in$ </tex-math></inline-formula> [0, −1]) simultaneously to generate two radiation beams, respectively. Through the detailed theoretical derivation of the radiation <inline-formula> <tex-math>$E$ </tex-math></inline-formula>-field based on the ±45°-slot unit of the EWG LWA, the polarization of the beam of the EWG LWA can be controlled. By utilizing a half-period interval between the two slots, the two beams have orthogonal polarizations and the same radiation gain. Moreover, following impedance match analysis, the stopband within the operating frequency band is also suppressed without affecting <inline-formula> <tex-math>$u = -1$ </tex-math></inline-formula> harmonic radiation, which expands the operating bandwidth of the dual-beam. By optimizing the stepped-slot structure, a stable gain can be achieved within the operating frequency band. For verification, an EWG LWA with <inline-formula> <tex-math>$pm45^{circ }$ </tex-math></inline-formula>-stepped-slot units centered at 5.5 GHz is designed. A good impedance matching (return loss >10 dB), high realized gain (>10 dBi), high total efficiency (>55%), stable gain (gain variation <3> <tex-math>$lt -16$ </tex-math></inline-formula> dB), and low envelope correlation coefficient (ECC, <0.007)> <tex-math>$2times 2$ </tex-math></inline-formula> MIMO system, achieving both spatial and polarization diversity, significantly enhancing channel capacity and robustness, enabling higher data rates for modern linear-cell communication systems.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1994-2006"},"PeriodicalIF":4.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154405","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":"Active Circulator GaN Front-Ends With Integrated Tunable Cancellers for Multifunction Phased Arrays","authors":"Kenneth E. Kolodziej;Laila Marzall;Zoya Popović","doi":"10.1109/TMTT.2025.3636855","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3636855","url":null,"abstract":"Multifunction phased array radar can add in-band full-duplex (IBFD) technology to eliminate the blind range that prevents it from detecting nearby objects. These advanced systems require unique front-end circuits to suppress the resulting self-interference (SI) and provide transmit-to-receive isolation. This article presents two active circulator monolithic microwave integrated circuits (MMICs) that contain integrated tunable cancellers with one and two canceller sections. The chips were fabricated in gallium nitride (GaN) and operate between 2.5 and 3.2 GHz. In addition to enabling an antenna to be shared between transmit and receive, they uniquely provide transmit and receive gains greater than 10 up to 20 dBm of transmit power output and roughly a 7-dB noise figure, as well as tunable transmit-to-receive isolation of more than 50 dB. The active circulator is also evaluated with a radar chirp waveform and, when combined with a subsequent digital cancellation filter, suppresses the SI by a total of 70 dB, within 1 dB of the receiver noise floor.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1917-1929"},"PeriodicalIF":4.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154474","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":"Signal-Signal Beating Interference: From Destructive to Constructive for Photonic THz Integrated Sensing and Communication System Using Self-Coherent OFDM","authors":"Fengwei Liu;Xihua Zou;Ningyuang Zhong;Xiong Deng;Lianshan Yan;Wei Pan","doi":"10.1109/TMTT.2025.3638469","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3638469","url":null,"abstract":"Terahertz (THz) integrated sensing and communication (ISAC) is a key building block for future 6G networks. In the traditional fiber or radio-over-fiber communication system, signal-signal beat interference (SSBI) is a critically destructive factor to be canceled. In this work, a nonlinear matched filtering (NMF) approach is proposed to transform the SSBI from a destructive interference into a constructive component for the THz ISAC system. By reusing the energy from the constructive SSBI, the NMF significantly enhances the sensing metrics in terms of the resolution and the peak-sidelobe ratio (PSLR). Using NMF can attain higher resolution with limited bandwidth; the larger the bandwidth, the better the effect. In experiments, a self-coherent ISAC system operating at 144-GHz center frequency and 5-GHz bandwidth is demonstrated with a 20-Gb/s communication capacity and a 1.94-cm ranging resolution. More importantly, the 3-dB resolution is improved by up to 25% and the PSLR is increased by up to 8 dB for the sensing function. In addition, the peak-to-average power ratio (PAPR) of the integrated signal is reduced by up to 7 dB.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1780-1789"},"PeriodicalIF":4.5,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154441","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":"2025 Index IEEE Transactions on Microwave Theory and Techniques Vol. 73","authors":"","doi":"10.1109/TMTT.2026.3674894","DOIUrl":"https://doi.org/10.1109/TMTT.2026.3674894","url":null,"abstract":"","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 12","pages":"1-227"},"PeriodicalIF":4.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11447479","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557557","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":"Bit-Wise Chipless RFID Tag Detection Based on Convolutional Neural Network and Synthetic Data","authors":"J. Junior Fodop Sokoudjou;Etienne Perret;Idoia Ochoa","doi":"10.1109/TMTT.2025.3634468","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3634468","url":null,"abstract":"This work presents a bit-wise chipless radio frequency identification (RFID) tag detection framework based on convolutional neural networks (CNNs). The proposed framework demonstrates two key capabilities: first, unlike previously proposed models, it allows decoding tag identifiers not used during the training phase of the models, making it possible to introduce a decoding method that could potentially be applied to detect high-capacity chipless tags; and second, it illustrates how synthetic data can be used to train models that generalize to real measurements, showing how instead of measuring each tag individually to construct a training dataset, data can instead be synthetically generated based on the knowledge of the tags’ design. Moreover, the framework includes a correction process to manage invalid predictions (i.e., those that are not part of the set of considered tags) and a probabilistic-based filtering process to identify uncertain predictions. Together, these strategies result in more confident predictions and fewer errors overall, showcasing the utility of error-correction strategies and the use of “soft” classifiers. The framework is assessed using different datasets for training: a dataset obtained from the recordings of S21 of wireless frequency-coded chipless RFID tags in a monostatic configuration, a synthetic dataset generated by modeling resonators as second-order bandpass filters, and a dataset made of the two previous datasets. All models are then employed to predict measurements made in a real-world setup. In the interval 20–50 cm, the model trained with real measurements achieves an accuracy of 99% after filtering, with a predictions conserved ratio (PCR) of 0.62; the one trained with synthetic measurements achieves an accuracy of 98% with a PCR of 0.61; and the one trained with a combination of real and synthetic measurements leads to an accuracy of 97% with a PCR of 0.70. If the distance is decreased (e.g., to 20–30 cm), higher accuracies and PCR values are obtained, as expected, achieving more than 99% accuracy after filtering in all cases. Overall, these results show how the proposed framework can correctly predict tags not seen during training, and how synthetic data can be used to train the models without harming their performance, while at the same time decreasing the time of measurement collection.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 2","pages":"1948-1961"},"PeriodicalIF":4.5,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154463","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}