Pub Date : 2025-04-30DOI: 10.1109/TMTT.2025.3561436
Samin Hanifi;Pedram Shirmohammadi;Steven M. Bowers
A detailed investigation of a method to effectively reduce additive phase noise in regenerative frequency dividers is presented. The approach enhances the sensitivity of conventional regenerative dividers and addresses start-up challenges while preserving low-additive phase noise and low power consumption. As a proof of concept, an integrated low-additive phase-noise regenerative divider with an octave-spanning frequency range was designed and fabricated using a 250-nm InP heterojunction bipolar transistor (HBT) process. The impact of the classes of operation for both the amplifier and the buffer, along with the effect of the phase shifter, on the divider’s overall phase-noise performance was analyzed and measured. The regenerative divider achieved additive phase noise below −163 dBc/Hz from a 7-GHz carrier at 10-kHz offset with more than 12-dB fundamental rejection and greater than −10-dBm output power at various frequencies. The presented results, with the full integration of the divider, address key challenges in low-additive phase-noise design, representing a significant advancement for low-noise applications, including communication and navigation systems.
{"title":"Additive Phase-Noise Reduction in Microwave Regenerative Dividers","authors":"Samin Hanifi;Pedram Shirmohammadi;Steven M. Bowers","doi":"10.1109/TMTT.2025.3561436","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3561436","url":null,"abstract":"A detailed investigation of a method to effectively reduce additive phase noise in regenerative frequency dividers is presented. The approach enhances the sensitivity of conventional regenerative dividers and addresses start-up challenges while preserving low-additive phase noise and low power consumption. As a proof of concept, an integrated low-additive phase-noise regenerative divider with an octave-spanning frequency range was designed and fabricated using a 250-nm InP heterojunction bipolar transistor (HBT) process. The impact of the classes of operation for both the amplifier and the buffer, along with the effect of the phase shifter, on the divider’s overall phase-noise performance was analyzed and measured. The regenerative divider achieved additive phase noise below −163 dBc/Hz from a 7-GHz carrier at 10-kHz offset with more than 12-dB fundamental rejection and greater than −10-dBm output power at various frequencies. The presented results, with the full integration of the divider, address key challenges in low-additive phase-noise design, representing a significant advancement for low-noise applications, including communication and navigation systems.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6326-6338"},"PeriodicalIF":4.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073434","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 : 2025-04-29DOI: 10.1109/TMTT.2025.3559211
Meiling Yang;Shenshen Luan;Xuchun Hao;Shuguo Xie;Yan Yang
Noncooperative electromagnetic radiation source sensing faces challenges such as wide bandwidth and an unknown number of sources, which hinder various applications like electromagnetic compatibility, radar detection, and passive positioning. Traditional sweep reception methods, based on antennas and superheterodyne receivers, struggle to meet real-time requirements. Optical undersampling sensing technologies enable rapid reception in ultrawideband. Frequency measurement in these systems, however, requires triple-comb or higher-dimensional information, introducing complexity and instability. The dual-comb-based frequency measurement method is further complicated by dead zones due to its underdetermined nature. In this article, we demonstrate, for the first time, the boundedness and reachability of the solution to the dual-comb ultrawideband frequency measurement problem. We propose a boundary determination method that ensures error-free solutions. Simulation and experimental results demonstrate that our method achieves 98% accuracy for a single source with seven octave bandwidths and over 90% accuracy for the coexistence of two-five sources. This method can achieve accurate measurement with only a 5 dB signal-to-noise ratio (SNR) and exhibits high robustness. Our work clearly defines the theoretical limits of frequency measurement for dual-comb undersampling systems, significantly enhancing both test accuracy and engineering practicability. This method can be widely applied to frequency measurement and signal estimation in RF and optical systems, paving new high-speed, accurate and robust pathways in microwave photonics metrology and ultrawideband signal processing.
{"title":"High-Accuracy Wideband Frequency Measurement With Dual Optical Combs Using Solution Space Partitioning Method","authors":"Meiling Yang;Shenshen Luan;Xuchun Hao;Shuguo Xie;Yan Yang","doi":"10.1109/TMTT.2025.3559211","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3559211","url":null,"abstract":"Noncooperative electromagnetic radiation source sensing faces challenges such as wide bandwidth and an unknown number of sources, which hinder various applications like electromagnetic compatibility, radar detection, and passive positioning. Traditional sweep reception methods, based on antennas and superheterodyne receivers, struggle to meet real-time requirements. Optical undersampling sensing technologies enable rapid reception in ultrawideband. Frequency measurement in these systems, however, requires triple-comb or higher-dimensional information, introducing complexity and instability. The dual-comb-based frequency measurement method is further complicated by dead zones due to its underdetermined nature. In this article, we demonstrate, for the first time, the boundedness and reachability of the solution to the dual-comb ultrawideband frequency measurement problem. We propose a boundary determination method that ensures error-free solutions. Simulation and experimental results demonstrate that our method achieves 98% accuracy for a single source with seven octave bandwidths and over 90% accuracy for the coexistence of two-five sources. This method can achieve accurate measurement with only a 5 dB signal-to-noise ratio (SNR) and exhibits high robustness. Our work clearly defines the theoretical limits of frequency measurement for dual-comb undersampling systems, significantly enhancing both test accuracy and engineering practicability. This method can be widely applied to frequency measurement and signal estimation in RF and optical systems, paving new high-speed, accurate and robust pathways in microwave photonics metrology and ultrawideband signal processing.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6759-6773"},"PeriodicalIF":4.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073210","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 : 2025-04-29DOI: 10.1109/TMTT.2025.3559956
Zuojun Wang;Zekun Li;Xiaoyue Xia;Jiayang Yu;Peigen Zhou;Jixin Chen;Yongxin Guo;Wei Hong
This article presents the analysis, design, and implementation of an integrated sub-THz frequency doubler. Using the VBIC model of the heterojunction bipolar transistor (HBT), we optimize the intrinsic base-emitter and collector-emitter voltage waveforms to maximize the second harmonic output power and further derive the optimal external input power sources and load terminals. We demonstrate that maximizing the second harmonic output power requires a purely capacitive fundamental load impedance. Furthermore, our analysis shows that applying optimal second harmonic input power can further enhance the second harmonic output power. To validate the theory, a frequency doubler is designed and fabricated using a 130-nm SiGe process. The doubler consists of a common-emitter push-push doubler core with an optimized fundamental load impedance, and a hybrid-mode driver amplifier to deliver both the fundamental and second harmonic input powers. The fabricated doubler chip exhibits a measured maximum saturated output power ($boldsymbol {{P}_{textbf {sat}}}$ ) of 8.2 dBm, with a measured $boldsymbol {{P}_{textbf {sat}}}~3$ -dB bandwidth ranging from 247 to 272 GHz. Compared with state-of-the-art doublers using the same SiGe process, the proposed doubler achieves the highest $boldsymbol {{P}_{textbf {sat}}}$ per unit emitter area and demonstrates a 1.6-fold improvement.
{"title":"A 247–272-GHz SiGe Frequency Doubler With 8.2-dBm Psat Enhanced by Optimized Fundamental Load Impedance and Hybrid-Mode Driver Amplifier","authors":"Zuojun Wang;Zekun Li;Xiaoyue Xia;Jiayang Yu;Peigen Zhou;Jixin Chen;Yongxin Guo;Wei Hong","doi":"10.1109/TMTT.2025.3559956","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3559956","url":null,"abstract":"This article presents the analysis, design, and implementation of an integrated sub-THz frequency doubler. Using the VBIC model of the heterojunction bipolar transistor (HBT), we optimize the intrinsic base-emitter and collector-emitter voltage waveforms to maximize the second harmonic output power and further derive the optimal external input power sources and load terminals. We demonstrate that maximizing the second harmonic output power requires a purely capacitive fundamental load impedance. Furthermore, our analysis shows that applying optimal second harmonic input power can further enhance the second harmonic output power. To validate the theory, a frequency doubler is designed and fabricated using a 130-nm SiGe process. The doubler consists of a common-emitter push-push doubler core with an optimized fundamental load impedance, and a hybrid-mode driver amplifier to deliver both the fundamental and second harmonic input powers. The fabricated doubler chip exhibits a measured maximum saturated output power (<inline-formula> <tex-math>$boldsymbol {{P}_{textbf {sat}}}$ </tex-math></inline-formula>) of 8.2 dBm, with a measured <inline-formula> <tex-math>$boldsymbol {{P}_{textbf {sat}}}~3$ </tex-math></inline-formula>-dB bandwidth ranging from 247 to 272 GHz. Compared with state-of-the-art doublers using the same SiGe process, the proposed doubler achieves the highest <inline-formula> <tex-math>$boldsymbol {{P}_{textbf {sat}}}$ </tex-math></inline-formula> per unit emitter area and demonstrates a 1.6-fold improvement.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6477-6490"},"PeriodicalIF":4.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073290","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 : 2025-04-29DOI: 10.1109/TMTT.2025.3554934
Jesus M. Jimenez-Suarez;Francisco Mesa;Oscar Quevedo-Teruel
We propose a systematic and efficient extension of the multimodal transfer-matrix method to obtain the dispersion diagram of structures with 2-D periodicity specifically targeted to primitive unit cells that possess internal symmetries. When symmetry planes can be applied, the study of the unit cell can be simplified to a number of 1D-periodic scenarios that depend on the boundary conditions imposed by the symmetry planes. The study of these 1D-periodic scenarios is simpler, more accurate, and requires less computational cost. The proposed methodology has been validated with different examples of periodic structures with different lattices (squared, rectangular, and hexagonal), symmetries, and motifs. Furthermore, this approach brings about a deeper understanding of the study of the Brillouin zone (BZ) and the relationship between phase shift and paths on its irreducible Brillouin zone (IBZ).
{"title":"A Symmetry-Based Multimodal Transfer-Matrix Method for the Analysis of 2D-Periodic Structures","authors":"Jesus M. Jimenez-Suarez;Francisco Mesa;Oscar Quevedo-Teruel","doi":"10.1109/TMTT.2025.3554934","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3554934","url":null,"abstract":"We propose a systematic and efficient extension of the multimodal transfer-matrix method to obtain the dispersion diagram of structures with 2-D periodicity specifically targeted to primitive unit cells that possess internal symmetries. When symmetry planes can be applied, the study of the unit cell can be simplified to a number of 1D-periodic scenarios that depend on the boundary conditions imposed by the symmetry planes. The study of these 1D-periodic scenarios is simpler, more accurate, and requires less computational cost. The proposed methodology has been validated with different examples of periodic structures with different lattices (squared, rectangular, and hexagonal), symmetries, and motifs. Furthermore, this approach brings about a deeper understanding of the study of the Brillouin zone (BZ) and the relationship between phase shift and paths on its irreducible Brillouin zone (IBZ).","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6234-6244"},"PeriodicalIF":4.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10980079","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073196","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}
Pub Date : 2025-04-28DOI: 10.1109/TMTT.2025.3562034
Srinaga Nikhil Nallandhigal;Fardin Ghorbani;Ke Wu
This article proposes a simple and efficient unified and integrated circuit antenna (UNICA) approach for achieving simultaneous front-end active circuitry and radiation functions in a unified design framework. This is accomplished by directly integrating the active device at optimal physical locations for required impedance matching in the multimode operation of the antenna. A systematic analysis of mode behavior, design flexibility, and radiation performance for various microstrip antennas is conducted. From this analysis, the rectangular patch antenna (RPA), operating in orthogonal modes, was selected as the most suitable radiator due to its ability to meet the desired performance criteria. The orthogonal mode operation of the RPA provides two isolated regions for the direct integration of the active device, allowing independent control over the corresponding impedance-matching condition at each terminal. A general modeling procedure for this unified solution is presented, followed by prototype demonstrations, including a class-A amplifier-antenna prototype operating at a resonant frequency of 5 GHz. Experimental results show that the prototype achieves an impedance-matched condition and delivers an amplification gain of 13 dB compared to its passive counterpart. These findings highlight the potential of this UNICA approach for efficient integration of amplification and radiation functions in a compact design.
{"title":"A Unified Architecture for Integrated Circuit and Radiation Function Using Co-Located Active Device and Multimode Antenna","authors":"Srinaga Nikhil Nallandhigal;Fardin Ghorbani;Ke Wu","doi":"10.1109/TMTT.2025.3562034","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3562034","url":null,"abstract":"This article proposes a simple and efficient unified and integrated circuit antenna (UNICA) approach for achieving simultaneous front-end active circuitry and radiation functions in a unified design framework. This is accomplished by directly integrating the active device at optimal physical locations for required impedance matching in the multimode operation of the antenna. A systematic analysis of mode behavior, design flexibility, and radiation performance for various microstrip antennas is conducted. From this analysis, the rectangular patch antenna (RPA), operating in orthogonal modes, was selected as the most suitable radiator due to its ability to meet the desired performance criteria. The orthogonal mode operation of the RPA provides two isolated regions for the direct integration of the active device, allowing independent control over the corresponding impedance-matching condition at each terminal. A general modeling procedure for this unified solution is presented, followed by prototype demonstrations, including a class-A amplifier-antenna prototype operating at a resonant frequency of 5 GHz. Experimental results show that the prototype achieves an impedance-matched condition and delivers an amplification gain of 13 dB compared to its passive counterpart. These findings highlight the potential of this UNICA approach for efficient integration of amplification and radiation functions in a compact design.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6931-6943"},"PeriodicalIF":4.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073321","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}
This article presents millimeter-wave (mmW) low-loss and sharp roll-off rectangular micro-coaxial line (R$mu $ CL) lowpass filters (LPFs) fabricated by the micro-structure electrochemical fabrication (MEFAB) process. The double stepped-impedance open stubs loaded resonator (DSIOSLR) is proposed to design R$mu $ CL LPFs. It consists of a pair of high-impedance lines with a pair of stepped-impedance open stubs (SIOSs) loaded at their center. The DSIOSLR, synthesized from a third-order Chebyshev lowpass prototype, achieves sharp roll-off and high stopband suppression due to the transmission zero (TZ) generated by SIOSs. Higher-order Chebyshev LPFs can be realized by cascading multiple DSIOSLRs. To validate the proposed method, five cascaded DSIOSLRs, six cascaded DSIOSLRs, and size_reduced DC-21 GHz R$mu $ CL LPFs are designed and fabricated. The simulated and measured results show good agreement. In the frequency range from dc to 20 GHz, the maximum insertion losses for the three R$mu $ CL LPFs are 0.62, 0.7, and 0.54 dB, respectively, and the corresponding normalized roll-off ratios are 252, 373, and 273 dB, respectively. For on-chip measurement and interconnection, an R$mu $ CL-to-coplanar waveguide grounded (CPWG) transition with a metal block for support enhancement is also proposed. As an example, a back-to-back R$mu $ CL-to-CPWG transition is fabricated, exhibiting a low loss of 0.2 dB from dc to 21 GHz and 0.5 dB up to 50 GHz.
{"title":"Millimeter-Wave Low-Loss and Sharp Roll-Off Rectangular Micro-Coaxial Line Lowpass Filters Using Micro-Structure Electrochemical Fabrication (MEFAB) Process","authors":"Jia-Hao Su;Jin Xu;Zi-Hao Zhou;Song-Yao Ji;Jia-Hao Zhao","doi":"10.1109/TMTT.2025.3560309","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3560309","url":null,"abstract":"This article presents millimeter-wave (mmW) low-loss and sharp roll-off rectangular micro-coaxial line (R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL) lowpass filters (LPFs) fabricated by the micro-structure electrochemical fabrication (MEFAB) process. The double stepped-impedance open stubs loaded resonator (DSIOSLR) is proposed to design R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula> CL LPFs. It consists of a pair of high-impedance lines with a pair of stepped-impedance open stubs (SIOSs) loaded at their center. The DSIOSLR, synthesized from a third-order Chebyshev lowpass prototype, achieves sharp roll-off and high stopband suppression due to the transmission zero (TZ) generated by SIOSs. Higher-order Chebyshev LPFs can be realized by cascading multiple DSIOSLRs. To validate the proposed method, five cascaded DSIOSLRs, six cascaded DSIOSLRs, and size_reduced DC-21 GHz R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL LPFs are designed and fabricated. The simulated and measured results show good agreement. In the frequency range from dc to 20 GHz, the maximum insertion losses for the three R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL LPFs are 0.62, 0.7, and 0.54 dB, respectively, and the corresponding normalized roll-off ratios are 252, 373, and 273 dB, respectively. For on-chip measurement and interconnection, an R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL-to-coplanar waveguide grounded (CPWG) transition with a metal block for support enhancement is also proposed. As an example, a back-to-back R<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>CL-to-CPWG transition is fabricated, exhibiting a low loss of 0.2 dB from dc to 21 GHz and 0.5 dB up to 50 GHz.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6615-6624"},"PeriodicalIF":4.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073241","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}
An origami-based metasurface retroreflector is proposed to realize highly efficient wideband back reflection. The design integrates origami-based gradient phase arrays that are articulated at angles of $boldsymbol {alpha = 25^{circ } }$ and $boldsymbol {beta = 45^{circ } }$ and constitutes a $20times 18$ array of resonant units. By morphing a 2-D surface into a quasi-planar configuration, the retroreflector significantly broadens its operational bandwidth and enhances backscattering capabilities. Simulations and experimental validations collectively demonstrate that the origami retroreflector provides a notable 21-dB enhancement in radar cross section (RCS) within the angular range of $ boldsymbol {45^{circ } pm 4^{circ } }$ . It exhibits a relative bandwidth of 18.87% under transverse electric (TE) polarization from 9.6 to 11.6 GHz and 15.81% under transverse magnetic (TM) polarization from 9.9 to 11.6 GHz. In addition, the retroreflector foldable nature allows for a substantial reduction in volume, reaching as low as 10% of its original size upon complete retraction. The proposed origami metasurface retroreflector exhibits potential applications in radar target detection, enemy identification, and maritime rescue due to its wideband RCS enhancement, lightweight structure, and foldable characteristics.
提出了一种基于折纸的超表面反反射器，以实现高效宽带反反射。该设计集成了以折纸为基础的梯度相阵，这些相阵以$boldsymbol {alpha = 25^{circ } }$和$boldsymbol {beta = 45^{circ } }$的角度铰接，构成了$20times 18$谐振单元阵列。通过将二维表面变形为准平面结构，后向反射器显着拓宽了其工作带宽并增强了后向散射能力。仿真和实验验证共同表明，折纸后向反射器在$ boldsymbol {45^{circ } pm 4^{circ } }$角范围内的雷达截面（RCS）显著提高了21 db。其相对带宽为18.87% under transverse electric (TE) polarization from 9.6 to 11.6 GHz and 15.81% under transverse magnetic (TM) polarization from 9.9 to 11.6 GHz. In addition, the retroreflector foldable nature allows for a substantial reduction in volume, reaching as low as 10% of its original size upon complete retraction. The proposed origami metasurface retroreflector exhibits potential applications in radar target detection, enemy identification, and maritime rescue due to its wideband RCS enhancement, lightweight structure, and foldable characteristics.
{"title":"Wideband and High-Efficiency Backscattering Enhancement Based on Origami Metasurface Retroreflector","authors":"Qingqing Zhang;Xiaobei Bian;Yusheng Yang;Jianbao Wang;He-Xiu Xu;Yongxiang Liu;Dongfang Guan","doi":"10.1109/TMTT.2025.3556886","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3556886","url":null,"abstract":"An origami-based metasurface retroreflector is proposed to realize highly efficient wideband back reflection. The design integrates origami-based gradient phase arrays that are articulated at angles of <inline-formula> <tex-math>$boldsymbol {alpha = 25^{circ } }$ </tex-math></inline-formula> and <inline-formula> <tex-math>$boldsymbol {beta = 45^{circ } }$ </tex-math></inline-formula> and constitutes a <inline-formula> <tex-math>$20times 18$ </tex-math></inline-formula> array of resonant units. By morphing a 2-D surface into a quasi-planar configuration, the retroreflector significantly broadens its operational bandwidth and enhances backscattering capabilities. Simulations and experimental validations collectively demonstrate that the origami retroreflector provides a notable 21-dB enhancement in radar cross section (RCS) within the angular range of <inline-formula> <tex-math>$ boldsymbol {45^{circ } pm 4^{circ } }$ </tex-math></inline-formula>. It exhibits a relative bandwidth of 18.87% under transverse electric (TE) polarization from 9.6 to 11.6 GHz and 15.81% under transverse magnetic (TM) polarization from 9.9 to 11.6 GHz. In addition, the retroreflector foldable nature allows for a substantial reduction in volume, reaching as low as 10% of its original size upon complete retraction. The proposed origami metasurface retroreflector exhibits potential applications in radar target detection, enemy identification, and maritime rescue due to its wideband RCS enhancement, lightweight structure, and foldable characteristics.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6847-6854"},"PeriodicalIF":4.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073182","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 : 2025-04-28DOI: 10.1109/TMTT.2025.3559476
Mohammad Marvasti;Halim Boutayeb
This work proposes a numerical technique for the analysis of Doppler radar systems, which are used in many applications, including but not limited to aircraft detection, vital signs monitoring, and hand gesture control. The proposed approach consists of using the finite-difference time-domain (FDTD) method with the implementation of moving objects, where the order of magnitude of the speed of light is considered for the numerical movements. This ensures that nonprohibitive computational time is required. The dynamic interactions between electromagnetic waves and moving targets are precisely captured. Medically accurate videos are used for heartbeat and respiration detections. Postprocessing is applied to obtain realistic radar responses, enabling the simulation results to closely mimic those measured by Doppler radars. Several problems are investigated and the numerical results are compared with experimental data reported in the literature. Additionally, an experimental setup is introduced for the analysis of the proposed numerical method, by using a Doppler radar and an object in motion that is video-recorded. The video is then inserted in the FDTD code to compare the simulated and experimental results. Two scenarios are studied: an oscillating metronome and hand gestures. The obtained results further validate the proposed method.
{"title":"Analysis of Doppler Radars With a Numerical Method","authors":"Mohammad Marvasti;Halim Boutayeb","doi":"10.1109/TMTT.2025.3559476","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3559476","url":null,"abstract":"This work proposes a numerical technique for the analysis of Doppler radar systems, which are used in many applications, including but not limited to aircraft detection, vital signs monitoring, and hand gesture control. The proposed approach consists of using the finite-difference time-domain (FDTD) method with the implementation of moving objects, where the order of magnitude of the speed of light is considered for the numerical movements. This ensures that nonprohibitive computational time is required. The dynamic interactions between electromagnetic waves and moving targets are precisely captured. Medically accurate videos are used for heartbeat and respiration detections. Postprocessing is applied to obtain realistic radar responses, enabling the simulation results to closely mimic those measured by Doppler radars. Several problems are investigated and the numerical results are compared with experimental data reported in the literature. Additionally, an experimental setup is introduced for the analysis of the proposed numerical method, by using a Doppler radar and an object in motion that is video-recorded. The video is then inserted in the FDTD code to compare the simulated and experimental results. Two scenarios are studied: an oscillating metronome and hand gestures. The obtained results further validate the proposed method.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6085-6093"},"PeriodicalIF":4.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073259","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}
In contrast to conventional phased array technology, frequency diverse array (FDA) presents a promising technology for addressing applications sensitive to distance. In order to generate FDA signals with a large bandwidth, as well as to solve the problem of beam decoupling in distance and angle, a novel microwave photonic (MWP) method designed for the generation of dual-carrier FDA signals is first proposed and experimentally verified. The innovative approach utilizes an integrated modulator to successfully produce 16-channel dual-carrier FDA signals, with a power flatness below 1.75 dB and a spurious signal suppression ratio of 35.17 dB. The resultant beampattern deviates from the conventional “S”-shaped pattern, adopting an “X”-shaped configuration instead. It is also demonstrated that increasing the number of array elements can significantly improve the resolution of the beampattern. Dual-carrier FDA signals with different frequency offsets and operating in distinct frequency bands (Ku and Ka bands) are successfully generated and experimentally validated. Furthermore, the capacity of generating 8–12-GHz wideband dual-carrier FDA signals is confirmed. The method further substantiates its versatility by successfully generating dual-carrier FDA signals with nonfixed frequency offsets, such as those based on square, reciprocal, and logarithmic functions. Challenges and prospects of the proposed scheme are also detailed discussed. By harnessing the inherent benefits of MWPs, the proposed method fulfills the demands of high bandwidth and anti-electromagnetic interference, which provide a promising method for future FDA applications.
{"title":"Wideband and Flexible Beamforming of Frequency Diverse Array Based on Microwave Photonic Dual-Carrier Signal Generation","authors":"Jiajun Tan;Weile Zhai;Xirui Zhong;Hao Yin;Xiaoyan Pang;Wanzhao Cui;Yongsheng Gao","doi":"10.1109/TMTT.2025.3559552","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3559552","url":null,"abstract":"In contrast to conventional phased array technology, frequency diverse array (FDA) presents a promising technology for addressing applications sensitive to distance. In order to generate FDA signals with a large bandwidth, as well as to solve the problem of beam decoupling in distance and angle, a novel microwave photonic (MWP) method designed for the generation of dual-carrier FDA signals is first proposed and experimentally verified. The innovative approach utilizes an integrated modulator to successfully produce 16-channel dual-carrier FDA signals, with a power flatness below 1.75 dB and a spurious signal suppression ratio of 35.17 dB. The resultant beampattern deviates from the conventional “S”-shaped pattern, adopting an “X”-shaped configuration instead. It is also demonstrated that increasing the number of array elements can significantly improve the resolution of the beampattern. Dual-carrier FDA signals with different frequency offsets and operating in distinct frequency bands (Ku and Ka bands) are successfully generated and experimentally validated. Furthermore, the capacity of generating 8–12-GHz wideband dual-carrier FDA signals is confirmed. The method further substantiates its versatility by successfully generating dual-carrier FDA signals with nonfixed frequency offsets, such as those based on square, reciprocal, and logarithmic functions. Challenges and prospects of the proposed scheme are also detailed discussed. By harnessing the inherent benefits of MWPs, the proposed method fulfills the demands of high bandwidth and anti-electromagnetic interference, which provide a promising method for future FDA applications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6774-6786"},"PeriodicalIF":4.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073381","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}
This article proposes and verifies the through superconducting substrate via (TSSV) technology for high-temperature superconducting (HTS) filters for the first time, which can be used to achieve vertical interconnection of superconducting substrates (YBCO/magnesium oxide (MgO)], advancing the design and manufacturing of HTS filters from 2-D plane to 3-D integration. The vertical interconnection between the top and bottom layers of the superconducting coplanar waveguide (CPW) lines is realized using TSSV. A dual-mode resonator based on TSSV is constructed, and the characteristic plane method (CPM) is proposed to uniquely distinguish multiple odd- and even-mode frequencies. A systematic study of the transverse cross-coupling structure is presented, through formula derivation, the influence of cross-coupling is separated from the total coupling, allowing for a clear analysis of its impact on the filter response. To validate the proposed methods, two- and four-stage transversal cross-coupling HTS filters are designed using TSSV. The measured results show excellent agreement with the design specifications.
{"title":"The Demonstration of Through Superconducting Substrate Via (TSSV) and Its Application to Transversal Cross-Coupling HTS Filter Design","authors":"Xilong Lu;Qingyu Kong;Guangsong Wei;Shigang Zhou;Liguo Zhou;Pengyu Ma;Qingyue Liu;Rui Zhang","doi":"10.1109/TMTT.2025.3557413","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3557413","url":null,"abstract":"This article proposes and verifies the through superconducting substrate via (TSSV) technology for high-temperature superconducting (HTS) filters for the first time, which can be used to achieve vertical interconnection of superconducting substrates (YBCO/magnesium oxide (MgO)], advancing the design and manufacturing of HTS filters from 2-D plane to 3-D integration. The vertical interconnection between the top and bottom layers of the superconducting coplanar waveguide (CPW) lines is realized using TSSV. A dual-mode resonator based on TSSV is constructed, and the characteristic plane method (CPM) is proposed to uniquely distinguish multiple odd- and even-mode frequencies. A systematic study of the transverse cross-coupling structure is presented, through formula derivation, the influence of cross-coupling is separated from the total coupling, allowing for a clear analysis of its impact on the filter response. To validate the proposed methods, two- and four-stage transversal cross-coupling HTS filters are designed using TSSV. The measured results show excellent agreement with the design specifications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6654-6667"},"PeriodicalIF":4.5,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073314","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}
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