A self-calibrated testing method for Mach–Zehnder modulator (MZM) chips operating up to 110 GHz is proposed based on fiber-free-coupled and self-pilot-based detection. Through introducing and tracking the self-pilot signal in the low-frequency region, the wideband combined frequency response of the cascaded microwave adapter network and the MZM chip under single-tone driving can be extracted without extra optical-to-electrical (O/E) calibration. In the system calibration, the one-port calibration consisting of the power-leveling technique and short–open–load (SOL) calibration is used to de-embed the uneven degradation response of the adapter network, which is attributed to impedance mismatch and transmission attenuation. Finally, the intrinsic half-wave voltage and relative frequency response are both extracted up to 110 GHz with sub-MHz photodetection. Using low-frequency photodetection with large-area photodetectors (PDs), fiber-free coupling replaces traditional waveguide-to-fiber coupling with single-mode-fiber pigtailed PDs, achieving better alignment tolerance without sacrificing performance. The proposed method features O/E self-calibration, single-tone modulation, and fiber-free coupling, which is favorable for on-chip microwave characterization of high-speed MZMs.
{"title":"Fiber-Free-Coupled and Self-Pilot-Based Detection for On-Chip Measurement of Mach–Zehnder Modulators Up to 110 GHz","authors":"Junfeng Zhu;Chao Jing;Simou Wang;Xinhai Zou;Yali Zhang;Sha Zhu;Yong Liu;Ning Hua Zhu;Shang Jian Zhang","doi":"10.1109/TMTT.2025.3622737","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3622737","url":null,"abstract":"A self-calibrated testing method for Mach–Zehnder modulator (MZM) chips operating up to 110 GHz is proposed based on fiber-free-coupled and self-pilot-based detection. Through introducing and tracking the self-pilot signal in the low-frequency region, the wideband combined frequency response of the cascaded microwave adapter network and the MZM chip under single-tone driving can be extracted without extra optical-to-electrical (O/E) calibration. In the system calibration, the one-port calibration consisting of the power-leveling technique and short–open–load (SOL) calibration is used to de-embed the uneven degradation response of the adapter network, which is attributed to impedance mismatch and transmission attenuation. Finally, the intrinsic half-wave voltage and relative frequency response are both extracted up to 110 GHz with sub-MHz photodetection. Using low-frequency photodetection with large-area photodetectors (PDs), fiber-free coupling replaces traditional waveguide-to-fiber coupling with single-mode-fiber pigtailed PDs, achieving better alignment tolerance without sacrificing performance. The proposed method features O/E self-calibration, single-tone modulation, and fiber-free coupling, which is favorable for on-chip microwave characterization of high-speed MZMs.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"975-983"},"PeriodicalIF":4.5,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049287","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}
Frequency-modulated continuous-wave (FMCW) radar has been widely used in motion sensing applications. However, inherent nonlinear errors can significantly degrade its performance. To the best of our knowledge, the impact of nonlinear frequency modulation (NLFM) on displacement motion sensing has not been studied. This article presents the first investigation into the influence of NLFM on displacement motion sensing, supported by theoretical derivations, simulations, and experimental validations. The linearity requirements for accurate motion sensing are analyzed and verified, providing theoretical guidance for displacement motion sensing applications. Building on the demonstrated robustness against NLFM, a voltage-controlled oscillator (VCO) in open-loop FMCW radar architecture is validated for displacement motion sensing. Comparative experiments show that, despite reduced hardware complexity, this architecture achieves performance comparable to that of VCO in closed-loop FMCW radar, with a normalized root-mean-squared error (NRMSE) difference below 1.6%. In robustness experiments, with ±0.2-V supply voltage variation and $9.5~^{circ }$ C temperature drop of VCO, this architecture still achieves precise motion sensing with an NRMSE below 3.2%. The miniaturized prototype based on this architecture successfully reconstructs differential microwave cardiograms (D-MCGs) and senses four types of gestures. These results demonstrate the architecture’s suitability for low-cost, low-complexity, high-accuracy, and compact short-range displacement motion sensing applications.
{"title":"Analysis and Experiments on the Impact of Frequency Nonlinearity on Displacement Motion Sensing With FMCW Radar","authors":"Zhiwei Zhang;Jingtao Liu;Jiayu Zhang;Yijing Guo;Changzhan Gu","doi":"10.1109/TMTT.2025.3622958","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3622958","url":null,"abstract":"Frequency-modulated continuous-wave (FMCW) radar has been widely used in motion sensing applications. However, inherent nonlinear errors can significantly degrade its performance. To the best of our knowledge, the impact of nonlinear frequency modulation (NLFM) on displacement motion sensing has not been studied. This article presents the first investigation into the influence of NLFM on displacement motion sensing, supported by theoretical derivations, simulations, and experimental validations. The linearity requirements for accurate motion sensing are analyzed and verified, providing theoretical guidance for displacement motion sensing applications. Building on the demonstrated robustness against NLFM, a voltage-controlled oscillator (VCO) in open-loop FMCW radar architecture is validated for displacement motion sensing. Comparative experiments show that, despite reduced hardware complexity, this architecture achieves performance comparable to that of VCO in closed-loop FMCW radar, with a normalized root-mean-squared error (NRMSE) difference below 1.6%. In robustness experiments, with ±0.2-V supply voltage variation and <inline-formula> <tex-math>$9.5~^{circ }$ </tex-math></inline-formula>C temperature drop of VCO, this architecture still achieves precise motion sensing with an NRMSE below 3.2%. The miniaturized prototype based on this architecture successfully reconstructs differential microwave cardiograms (D-MCGs) and senses four types of gestures. These results demonstrate the architecture’s suitability for low-cost, low-complexity, high-accuracy, and compact short-range displacement motion sensing applications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"1154-1166"},"PeriodicalIF":4.5,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049303","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}
Pub Date : 2025-10-31DOI: 10.1109/TMTT.2025.3624870
Bohui Guo;Junjie Wang;Ran Sui;Yan Ma;Dejun Feng
Temporal-coded metasurface (TCM) provides a new paradigm for radar target feature modulation through dynamic electromagnetic parameter control. However, the false peaks generated by TCM modulation are limited by the sinc envelope constraint of the Fourier transform, and the regular false peaks are easily filtered out by constant false alarm rate (CFAR) detectors. This article proposes a nonuniform bipulse modulation waveform based on the TCM, and the core innovation lies in introducing a time-delay factor $gamma $ as the core degree of freedom to construct a time-domain encoded sequence with nonuniform pulse intervals. This design breaks the periodic constraints of traditional uniform modulation from a physical perspective, enabling nonuniform distribution of echo energy in the feature space and significantly improving the randomness and flexibility of amplitude distribution of the false peaks. Microwave darkroom experiments have shown that by adjusting the time-delay factor and duty cycle, the amplitude of specific harmonic false peaks can be precisely controlled and even eliminated. Finally, CFAR detection further confirms its ability to significantly increase the number of effective false peaks, providing a new approach to breaking through the bottleneck of radar adaptive anti-interference.
{"title":"Nonuniform Bipulse Modulation on Temporal-Coded Metasurface Against Radar CFAR Detection","authors":"Bohui Guo;Junjie Wang;Ran Sui;Yan Ma;Dejun Feng","doi":"10.1109/TMTT.2025.3624870","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3624870","url":null,"abstract":"Temporal-coded metasurface (TCM) provides a new paradigm for radar target feature modulation through dynamic electromagnetic parameter control. However, the false peaks generated by TCM modulation are limited by the sinc envelope constraint of the Fourier transform, and the regular false peaks are easily filtered out by constant false alarm rate (CFAR) detectors. This article proposes a nonuniform bipulse modulation waveform based on the TCM, and the core innovation lies in introducing a time-delay factor <inline-formula> <tex-math>$gamma $ </tex-math></inline-formula> as the core degree of freedom to construct a time-domain encoded sequence with nonuniform pulse intervals. This design breaks the periodic constraints of traditional uniform modulation from a physical perspective, enabling nonuniform distribution of echo energy in the feature space and significantly improving the randomness and flexibility of amplitude distribution of the false peaks. Microwave darkroom experiments have shown that by adjusting the time-delay factor and duty cycle, the amplitude of specific harmonic false peaks can be precisely controlled and even eliminated. Finally, CFAR detection further confirms its ability to significantly increase the number of effective false peaks, providing a new approach to breaking through the bottleneck of radar adaptive anti-interference.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"1054-1068"},"PeriodicalIF":4.5,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049294","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}
Wi-Fi sensor node (SN) identification is necessary for efficient beam control in analog beam forming for wireless Internet of Things (IoT) communication. A method for SN identification using Wi-Fi backscatter, incorporating self-mixing with the backscattered signal from SN and the transmitted (Tx) Wi-Fi signal, has been proposed for efficient multiple SN identification. The method can be easily applied by just adding an RF switch and clock oscillator to the backscatter module without changing the Wi-Fi communication standard. To theoretically reveal the principle, this article proposes a simplified analysis model, assuming the mixer operates ideally as a multiplier. Based on the proposed model, the self-mixing signal spectrum can be simulated, and its signal-to-noise ratio (SNR) is estimated. In a multicarrier modulation (e.g., IEEE802.11g) situation, intermodulation of its subcarriers affects SNR by self-mixing. The noise distribution can also be analyzed by the proposed model. We evaluate the model by measurement with IEEE802.11g (2.4-GHz band) Wi-Fi signal using the fabricated backscatter module and confirm that the measured SNR shows a good agreement with the proposed model.
{"title":"Simplified Model and Its Evaluation of Wi-Fi Sensor Node Identification Method Using Wi-Fi Backscatter and Self-Mixing Receiver","authors":"Yuki Fujiya;Koki Edamatsu;Tomoyuki Furuichi;Takashi Shiba;Noriharu Suematsu","doi":"10.1109/TMTT.2025.3619412","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3619412","url":null,"abstract":"Wi-Fi sensor node (SN) identification is necessary for efficient beam control in analog beam forming for wireless Internet of Things (IoT) communication. A method for SN identification using Wi-Fi backscatter, incorporating self-mixing with the backscattered signal from SN and the transmitted (Tx) Wi-Fi signal, has been proposed for efficient multiple SN identification. The method can be easily applied by just adding an RF switch and clock oscillator to the backscatter module without changing the Wi-Fi communication standard. To theoretically reveal the principle, this article proposes a simplified analysis model, assuming the mixer operates ideally as a multiplier. Based on the proposed model, the self-mixing signal spectrum can be simulated, and its signal-to-noise ratio (SNR) is estimated. In a multicarrier modulation (e.g., IEEE802.11g) situation, intermodulation of its subcarriers affects SNR by self-mixing. The noise distribution can also be analyzed by the proposed model. We evaluate the model by measurement with IEEE802.11g (2.4-GHz band) Wi-Fi signal using the fabricated backscatter module and confirm that the measured SNR shows a good agreement with the proposed model.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"1110-1120"},"PeriodicalIF":4.5,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049296","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}
Pub Date : 2025-10-30DOI: 10.1109/TMTT.2025.3618460
Tom Shvartzman;Erez Zolkov;Emanuel Cohen
This work presents a technique for reciprocal mixing (RM) cancellation caused by the interaction of close-in phase noise (PN) with a strong out-of-band (OOB) blocker, leveraging local oscillator (LO) delay and the baseband (BB) impedance transparency of N-path filters. By connecting two N-path filters with 90° phase shift (PS) elements and introducing LO delay, a separation is created between the signal and RM content in the BB portion. This enables digital-domain RM cancellation with minimal noise figure (NF) penalty. Implemented in 65-nm TSMC, the proposed technique achieves 16–17-dB RM suppression, with NF increase of approximately 2 dB over the 3-dB NF of a standalone N-path mixer-based receiver, yielding a total NF of 5 dB. The RM suppression is achieved for a 1-dBm blocker located 270 MHz from the 1-GHz in-band frequency while using an LO delay of 0.65 ns.
{"title":"Wideband N-Path Receiver With Reciprocal Mixing Phase Noise Cancellation and Reduced Delay Path","authors":"Tom Shvartzman;Erez Zolkov;Emanuel Cohen","doi":"10.1109/TMTT.2025.3618460","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3618460","url":null,"abstract":"This work presents a technique for reciprocal mixing (RM) cancellation caused by the interaction of close-in phase noise (PN) with a strong out-of-band (OOB) blocker, leveraging local oscillator (LO) delay and the baseband (BB) impedance transparency of N-path filters. By connecting two N-path filters with 90° phase shift (PS) elements and introducing LO delay, a separation is created between the signal and RM content in the BB portion. This enables digital-domain RM cancellation with minimal noise figure (NF) penalty. Implemented in 65-nm TSMC, the proposed technique achieves 16–17-dB RM suppression, with NF increase of approximately 2 dB over the 3-dB NF of a standalone N-path mixer-based receiver, yielding a total NF of 5 dB. The RM suppression is achieved for a 1-dBm blocker located 270 MHz from the 1-GHz in-band frequency while using an LO delay of 0.65 ns.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"1098-1109"},"PeriodicalIF":4.5,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049299","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}
Pub Date : 2025-10-28DOI: 10.1109/TMTT.2025.3620573
Changlong Du;Shifeng Liu;Li Yang;Mingzhen Liu;Liangzun Tang;Hao Chen;Shilong Pan
We propose and experimentally demonstrate a novel method for coherent dual-band microwave pulse signal generation with variable repetition rates based on an actively mode-locked optoelectronic oscillator (OEO). In the proposed structure, the carrier frequencies of the dual-band signal are determined by a dual-band bandpass filter (DB-BPF) embedded in the OEO loop. Stable oscillation and phase coherence between the two carrier frequencies are achieved through mutual frequency conversion and energy coupling induced by an injection signal applied to the intracavity MachZehnder modulator (MZM), whose frequency equals the interval between the two carriers. Simultaneously, microwave pulse signal generation is realized by applying an additional low-frequency electrical waveform to the bias port of MZM for active mode-locking. This signal is tuned so that its frequency aligns with an integer multiple of the oscillation loop’s free spectral range (FSR). In a proof-of-concept experiment, coherent dual-band microwave pulse signals with carrier frequencies of 10 and 16.091 GHz are generated. Different pulses repetition rates of 100.3, 200.6, and 501.5 kHz are achieved through fundamental, second-order harmonic, and fifth-order harmonic mode-locking, respectively. Furthermore, coherent dual-band staggered double-pulses within one cavity period are successfully generated. The phase noise of the generated microwave pulse signal was measured to be below −139 dBc/Hz at a 10 kHz offset frequency.
{"title":"Coherent Dual-Band Microwave Pulse Signal Generation Based on an Actively Mode-Locked Optoelectronic Oscillator","authors":"Changlong Du;Shifeng Liu;Li Yang;Mingzhen Liu;Liangzun Tang;Hao Chen;Shilong Pan","doi":"10.1109/TMTT.2025.3620573","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3620573","url":null,"abstract":"We propose and experimentally demonstrate a novel method for coherent dual-band microwave pulse signal generation with variable repetition rates based on an actively mode-locked optoelectronic oscillator (OEO). In the proposed structure, the carrier frequencies of the dual-band signal are determined by a dual-band bandpass filter (DB-BPF) embedded in the OEO loop. Stable oscillation and phase coherence between the two carrier frequencies are achieved through mutual frequency conversion and energy coupling induced by an injection signal applied to the intracavity MachZehnder modulator (MZM), whose frequency equals the interval between the two carriers. Simultaneously, microwave pulse signal generation is realized by applying an additional low-frequency electrical waveform to the bias port of MZM for active mode-locking. This signal is tuned so that its frequency aligns with an integer multiple of the oscillation loop’s free spectral range (FSR). In a proof-of-concept experiment, coherent dual-band microwave pulse signals with carrier frequencies of 10 and 16.091 GHz are generated. Different pulses repetition rates of 100.3, 200.6, and 501.5 kHz are achieved through fundamental, second-order harmonic, and fifth-order harmonic mode-locking, respectively. Furthermore, coherent dual-band staggered double-pulses within one cavity period are successfully generated. The phase noise of the generated microwave pulse signal was measured to be below −139 dBc/Hz at a 10 kHz offset frequency.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"931-938"},"PeriodicalIF":4.5,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049265","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}
Ensuring information security has long been a critical challenge in wireless networks. Due to its strong confidentiality, wireless communication using modulated thermal noise has recently garnered significant attention. Despite substantial theoretical advances, the practical implementation of thermal noise-based wireless communication systems remains limited. By establishing the theoretical framework for noise carrier wireless communication (NCWCom), this article presents an initial covert communication system using modulated thermal noise. By amplifying the thermal noise generated by a matched load, NCWCom can achieve high-speed, long-distance wireless communication. We validate the feasibility and effectiveness of NCWCom using a Ka-band initial system with on-off-keying (OOK) modulation and energy detection, demonstrating wireless transmission of image data. A close match is observed between the measured bit error rate (BER) and the bit error probability (BEP) derived from theoretical analysis. The inherent trade-offs between communication performance and signal concealment are also discussed. In addition, we analyze the probability of noncooperative detection of NCWCom signals within the energy detection framework, and we address various details pertaining to system implementation. This work provides meaningful guidance for the advancement of secure and covert wireless communication technologies.
{"title":"Initial System and Results of Covert Wireless Communication Using Modulated Thermal Noise","authors":"Hanchi Ma;Yayun Cheng;Zhe Jiang;Shuang Qiu;Nannan Wang;Kam-Weng Tam;Jinghui Qiu","doi":"10.1109/TMTT.2025.3620599","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3620599","url":null,"abstract":"Ensuring information security has long been a critical challenge in wireless networks. Due to its strong confidentiality, wireless communication using modulated thermal noise has recently garnered significant attention. Despite substantial theoretical advances, the practical implementation of thermal noise-based wireless communication systems remains limited. By establishing the theoretical framework for noise carrier wireless communication (NCWCom), this article presents an initial covert communication system using modulated thermal noise. By amplifying the thermal noise generated by a matched load, NCWCom can achieve high-speed, long-distance wireless communication. We validate the feasibility and effectiveness of NCWCom using a Ka-band initial system with on-off-keying (OOK) modulation and energy detection, demonstrating wireless transmission of image data. A close match is observed between the measured bit error rate (BER) and the bit error probability (BEP) derived from theoretical analysis. The inherent trade-offs between communication performance and signal concealment are also discussed. In addition, we analyze the probability of noncooperative detection of NCWCom signals within the energy detection framework, and we address various details pertaining to system implementation. This work provides meaningful guidance for the advancement of secure and covert wireless communication technologies.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"1121-1134"},"PeriodicalIF":4.5,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049262","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}
A novel beamforming network (BFN) architecture based on the phase difference tuner (PDT) radio frequency integrated circuits (RFICs) for a large phased array antenna (PAA) is proposed. This work is the development of the first BFN architecture based on PDT RFICs, which provides advantages in achieving higher gain and reducing component counts compared with the conventional architecture using vector-sum phase shifters (VSPSs). The novelty of the proposed BFN architecture lies in the simultaneous fulfillment of two key conditions: 1) the PDT RFIC simultaneously performs phase tuning and power splitting without increasing the component counts compared to the conventional VSPS and 2) the beamforming mechanism of the proposed architecture positions the PDT RFIC at each power division point and controls the phase difference between two output ports. The novelty enables high-gain advantages arising from two main factors: 1) the elimination of additional multistage power dividers, which significantly reduces cumulative insertion loss; and 2) a multistage amplification mechanism through cascading of PDTs, based on the beamforming mechanism of the proposed architecture. Based on the advantage of eliminating additional multistage power dividers, the architectural innovation inherently achieves higher gain compared to conventional architectures using VSPSs. To validate the high-gain performance of the proposed architecture, a $16times 8$ 1-D PAA is proposed. This array achieves high gain (>40 dB), wide bandwidth (30.5–38 GHz), narrow beamwidth (6°), and scanning angle up to 55°. Compared with other related works using VSPSs, the proposed BFN architecture offers a significant advantage in the gain of the BFN for a large-scale PAA.
{"title":"A Millimeter-Wave High-Gain and Wideband 16 × 8 Phased Array Antenna Without Additional Multistage Power Dividers Using Novel Beamforming Network Architecture Based on Phase Difference Tuners","authors":"Ching-Cheng Hsu;Jenn-Hwan Tarng;Chia-Hsuan Cheng;Zuo-Min Tsai","doi":"10.1109/TMTT.2025.3622968","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3622968","url":null,"abstract":"A novel beamforming network (BFN) architecture based on the phase difference tuner (PDT) radio frequency integrated circuits (RFICs) for a large phased array antenna (PAA) is proposed. This work is the development of the first BFN architecture based on PDT RFICs, which provides advantages in achieving higher gain and reducing component counts compared with the conventional architecture using vector-sum phase shifters (VSPSs). The novelty of the proposed BFN architecture lies in the simultaneous fulfillment of two key conditions: 1) the PDT RFIC simultaneously performs phase tuning and power splitting without increasing the component counts compared to the conventional VSPS and 2) the beamforming mechanism of the proposed architecture positions the PDT RFIC at each power division point and controls the phase difference between two output ports. The novelty enables high-gain advantages arising from two main factors: 1) the elimination of additional multistage power dividers, which significantly reduces cumulative insertion loss; and 2) a multistage amplification mechanism through cascading of PDTs, based on the beamforming mechanism of the proposed architecture. Based on the advantage of eliminating additional multistage power dividers, the architectural innovation inherently achieves higher gain compared to conventional architectures using VSPSs. To validate the high-gain performance of the proposed architecture, a <inline-formula> <tex-math>$16times 8$ </tex-math></inline-formula> 1-D PAA is proposed. This array achieves high gain (>40 dB), wide bandwidth (30.5–38 GHz), narrow beamwidth (6°), and scanning angle up to 55°. Compared with other related works using VSPSs, the proposed BFN architecture offers a significant advantage in the gain of the BFN for a large-scale PAA.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"1069-1085"},"PeriodicalIF":4.5,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11219283","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049278","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}
Microwave parameter measurement of electromagnetic targets has always been an important task in electronic reconnaissance and radar systems. Signal processing methods based on analog photonics technology have attracted widespread attention because they avoid the bandwidth bottlenecks and processing delays associated with analog-to-digital conversion and digital signal processing. However, most early photonics microwave parameter measurement methods were based on single-tone pilot signals and did not fully utilize the broadband advantages of photonic technology. In view of this, we first propose an unambiguous multidimensional microwave parameter measurement method for multiple targets based on photonic fractional Fourier transform (FrFT) in a wideband photonic radar system, which can simultaneously achieve Doppler frequency shift (DFS) and angle of arrival (AOA) measurements as well as high-precision 1-D distance imaging. The scheme fully exploits the analytical advantages of FrFT in handling linear frequency modulated (LFM) signals with large time-bandwidth products. By constructing an equivalent FrFT kernel to process broadband echo signals with multiple targets, blur-free parameter measurement is achieved. In addition, the 1-GHz upshifting of the acousto-optic frequency shifter (AOFS) effectively avoids FrFT self-interference between multitarget echo signals. Experimental results demonstrate that within the frequency band from 7 to 30 GHz, the system achieves accurate measurement of DFS values and directions, with a maximum measurement error of 0.15 Hz. Unambiguous AOA measurement is completed within the range of −77.16° to 77.16°, with the absolute error controlled within 2.73°. Meanwhile, the system realizes 1-D range imaging of targets, achieving a measured range resolution of 0.5 m, close to the theoretical value of 0.3 m. The research achieves highly integrated multiparameter measurement under an active detection framework, significantly enhancing the accuracy and efficiency of target detection, and providing new technical approaches and implementation schemes for future development of multifunctional integrated detection technologies.
{"title":"Unambiguous Multidimensional Microwave Parameter Measurement for Multiple Targets Based on Photonic Fractional Fourier Transform","authors":"Weile Zhai;Hao Yin;Jiajun Tan;Xinyao Li;Xiaoyan Pang;Yongsheng Gao","doi":"10.1109/TMTT.2025.3623598","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3623598","url":null,"abstract":"Microwave parameter measurement of electromagnetic targets has always been an important task in electronic reconnaissance and radar systems. Signal processing methods based on analog photonics technology have attracted widespread attention because they avoid the bandwidth bottlenecks and processing delays associated with analog-to-digital conversion and digital signal processing. However, most early photonics microwave parameter measurement methods were based on single-tone pilot signals and did not fully utilize the broadband advantages of photonic technology. In view of this, we first propose an unambiguous multidimensional microwave parameter measurement method for multiple targets based on photonic fractional Fourier transform (FrFT) in a wideband photonic radar system, which can simultaneously achieve Doppler frequency shift (DFS) and angle of arrival (AOA) measurements as well as high-precision 1-D distance imaging. The scheme fully exploits the analytical advantages of FrFT in handling linear frequency modulated (LFM) signals with large time-bandwidth products. By constructing an equivalent FrFT kernel to process broadband echo signals with multiple targets, blur-free parameter measurement is achieved. In addition, the 1-GHz upshifting of the acousto-optic frequency shifter (AOFS) effectively avoids FrFT self-interference between multitarget echo signals. Experimental results demonstrate that within the frequency band from 7 to 30 GHz, the system achieves accurate measurement of DFS values and directions, with a maximum measurement error of 0.15 Hz. Unambiguous AOA measurement is completed within the range of −77.16° to 77.16°, with the absolute error controlled within 2.73°. Meanwhile, the system realizes 1-D range imaging of targets, achieving a measured range resolution of 0.5 m, close to the theoretical value of 0.3 m. The research achieves highly integrated multiparameter measurement under an active detection framework, significantly enhancing the accuracy and efficiency of target detection, and providing new technical approaches and implementation schemes for future development of multifunctional integrated detection technologies.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"74 1","pages":"960-974"},"PeriodicalIF":4.5,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049282","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}
Pub Date : 2025-10-28DOI: 10.1109/TMTT.2025.3620633
Muhammad Uzair;Hanxiang Zhang;Ayesha Naseem;Bayaner Arigong
A true time delay (TTD) beamforming network is proposed from an RF signal processing time-delay block (TDB), which is composed of an RF Hilbert transformer and a tunable transmission line. Here, the RF Hilbert transformer in TDB rotates the electromagnetic waveform by 180° directly in the analog domain without changing its magnitude. To extend the tunable time-delay range, multiple TDBs are cascaded to form a true time-delay network (TDN), realizing the desired time-delay range for a 360° phase change. The theoretical analysis is conducted to explain the RF signal processing TTD and the total time-delay range of TDN. A $1times 4$ true TDN prototype operating at WiFi frequencies is designed, fabricated, and tested to validate the design concept, and its radiation pattern is measured with integration of a microstrip patch antenna array. The measured beam steering network covers a range of approximately ±45° with minimal beam squinting and variation in the gain. All the simulation and measurement results align well with each other to validate the proposed TTD design topology.
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