Pub Date : 2022-08-12DOI: 10.1109/ICMMT55580.2022.10022623
Bin Yuan, Peng Wu, Yang Yuan, Chunshuang Xie, Zhongjun Yu
In this paper, an improved integration solution is proposed to integrate millimeter-wave (MMW)/terahertz (THz) monolithic microwave integrated circuit (MMIC) with rectangular waveguide (RWG). A new via-less end-wall MS-RWG interconnection with multiple open stubs is explored to eliminate the use of via holes in higher frequency band, and thus breaks through the limitation of low-loss and wideband applications. And moreover, the bandwidth is further expanded by the open stubs with different lengths. A 340 GHz interconnection is designed and fabricated as an example for the MMIC-to-RWG application. The measured insertion loss and return loss are respectively better than 0.9 dB and 12 dB from 314GHz to 369 GHz after the microstrip transmission lines in the test fixture are calibrated. The proposed integration solution brings benefits of wideband performance, easy manufacture and low cost, which has potential applications in MMW/THz microsystems.
{"title":"Improved MMIC-to-Waveguide Integration Solution for Millimeter-wave/Terahertz Applications","authors":"Bin Yuan, Peng Wu, Yang Yuan, Chunshuang Xie, Zhongjun Yu","doi":"10.1109/ICMMT55580.2022.10022623","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10022623","url":null,"abstract":"In this paper, an improved integration solution is proposed to integrate millimeter-wave (MMW)/terahertz (THz) monolithic microwave integrated circuit (MMIC) with rectangular waveguide (RWG). A new via-less end-wall MS-RWG interconnection with multiple open stubs is explored to eliminate the use of via holes in higher frequency band, and thus breaks through the limitation of low-loss and wideband applications. And moreover, the bandwidth is further expanded by the open stubs with different lengths. A 340 GHz interconnection is designed and fabricated as an example for the MMIC-to-RWG application. The measured insertion loss and return loss are respectively better than 0.9 dB and 12 dB from 314GHz to 369 GHz after the microstrip transmission lines in the test fixture are calibrated. The proposed integration solution brings benefits of wideband performance, easy manufacture and low cost, which has potential applications in MMW/THz microsystems.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129916165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/ICMMT55580.2022.10022669
Qiang Chen, Wei-Hang Zhou, Peng Xu
In this work, a high aperture efficiency Fabry-Perot resonator cavity antenna (FPRCA) with a single-layer nonuniform metasurface superstrate is proposed. The nonuniform superstrate is designed with different reflection amplitudes as well as maintain a constant reflection phase to uniformize the antenna aperture electric field distribution and realize high gain as well as high aperture efficiency. To validate the proposed single-layer nonuniform metasurface superstrate, a 10 GHz FPRCA is simulated and designed with 4 λ× 4 λ aperture size. At the working frequency of 10 GHz, the gain of the FPRCA is 22.4 dBi -and the aperture efficiency is up to 86.4%. Compared to the previous published high-gain and high-aperture efficiency FPRCAs with multilayer superstrate, the proposed FPRCA simultaneously realizes high gain as well as high aperture efficiency with a single-layer superstrate.
{"title":"A High-Directivity and High-Aperture Efficiency Fabry-Perot Resonator Cavity Antenna with Single-Layer Nonuniform Metasurface Superstrate","authors":"Qiang Chen, Wei-Hang Zhou, Peng Xu","doi":"10.1109/ICMMT55580.2022.10022669","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10022669","url":null,"abstract":"In this work, a high aperture efficiency Fabry-Perot resonator cavity antenna (FPRCA) with a single-layer nonuniform metasurface superstrate is proposed. The nonuniform superstrate is designed with different reflection amplitudes as well as maintain a constant reflection phase to uniformize the antenna aperture electric field distribution and realize high gain as well as high aperture efficiency. To validate the proposed single-layer nonuniform metasurface superstrate, a 10 GHz FPRCA is simulated and designed with 4 λ× 4 λ aperture size. At the working frequency of 10 GHz, the gain of the FPRCA is 22.4 dBi -and the aperture efficiency is up to 86.4%. Compared to the previous published high-gain and high-aperture efficiency FPRCAs with multilayer superstrate, the proposed FPRCA simultaneously realizes high gain as well as high aperture efficiency with a single-layer superstrate.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130337982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/ICMMT55580.2022.10022467
Jin Zhao, Ming-Zhe Chong, Zi‐Wen Zhang, Pu‐Kun Liu
Orbital angular momentum (OAM) is a kind of momentum which is generally carried by electromagnetic waves. Since OAM has the potential to satisfy the demand of channel capacity, it has attracted more and more attention recently. The demand of generating the OAM mode is growing rapidly. In this work, we study the OAM generated by the localized spoof surface plasmons in curved meanderline with a special excitation. As a result, an orbital angular momentum mode with the topological charge being 2 is generated, which may be further extend to higher modes and may provide a potential way for the multiplex communication and object feature detection.
{"title":"A Method of generating orbital angular momentum based on curved Meanderline","authors":"Jin Zhao, Ming-Zhe Chong, Zi‐Wen Zhang, Pu‐Kun Liu","doi":"10.1109/ICMMT55580.2022.10022467","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10022467","url":null,"abstract":"Orbital angular momentum (OAM) is a kind of momentum which is generally carried by electromagnetic waves. Since OAM has the potential to satisfy the demand of channel capacity, it has attracted more and more attention recently. The demand of generating the OAM mode is growing rapidly. In this work, we study the OAM generated by the localized spoof surface plasmons in curved meanderline with a special excitation. As a result, an orbital angular momentum mode with the topological charge being 2 is generated, which may be further extend to higher modes and may provide a potential way for the multiplex communication and object feature detection.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130556283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/ICMMT55580.2022.10022512
Zhang Yanyan, Wang Huai
This paper proposes a novel quad-band circularly polarized antenna for Global Navigation Satellite System (GNSS), covering multiple standard frequency bands for GPS, Galileo and BeiDou systems. The antenna is probe fed with a stacked structure. We use three orthogonal feed network antennas with a 90 ° phase difference and a Corner-cut microstrip antenna to realize circular polarization in four frequency bands. The whole antenna shows good impedance matching and axial ratio characteristics, and also has the advantages of compact structure and low cost and can be applied in different satellite navigation systems.
{"title":"Quad-Band Circular Polarized Antenna for Multi-navigation System","authors":"Zhang Yanyan, Wang Huai","doi":"10.1109/ICMMT55580.2022.10022512","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10022512","url":null,"abstract":"This paper proposes a novel quad-band circularly polarized antenna for Global Navigation Satellite System (GNSS), covering multiple standard frequency bands for GPS, Galileo and BeiDou systems. The antenna is probe fed with a stacked structure. We use three orthogonal feed network antennas with a 90 ° phase difference and a Corner-cut microstrip antenna to realize circular polarization in four frequency bands. The whole antenna shows good impedance matching and axial ratio characteristics, and also has the advantages of compact structure and low cost and can be applied in different satellite navigation systems.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126816682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we propose an active spoof magnetic localized surface plasmonic metamaterial that can realize the dynamic control of electric and magnetic resonances in an ultrathin corrugated metallic spiral disk. Active component of varactor has been loaded into such metallic spiral disk structure. By changing the supplied voltages of the active devices, the resonant frequencies of the electric- and magnetic-dipole can be dynamically tuned, thereby flexibly controlling the multipole interference of electric and magnetic resonances. Experimental results are in good agreement with the simulated ones.
{"title":"Active Spoof Magnetic Localized Surface Plasmons","authors":"Jinrui Shen, Liangliang Liu, Zixiang Zhou, Xinhua Li, Yuan Feng, Guodong Han, Zhuo Li","doi":"10.1109/ICMMT55580.2022.10023296","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10023296","url":null,"abstract":"In this work, we propose an active spoof magnetic localized surface plasmonic metamaterial that can realize the dynamic control of electric and magnetic resonances in an ultrathin corrugated metallic spiral disk. Active component of varactor has been loaded into such metallic spiral disk structure. By changing the supplied voltages of the active devices, the resonant frequencies of the electric- and magnetic-dipole can be dynamically tuned, thereby flexibly controlling the multipole interference of electric and magnetic resonances. Experimental results are in good agreement with the simulated ones.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129108047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A multistate tunable low-scattering metasurface is designed with characteristic mode theory (CMT) in this paper. By analyzing the surface currents and mode excitation coefficients of the structure, the value and load position of impedance are guided to achieve a low-scattering design. Furthermore, the metasurface can be switched between different scattering states and operating bands by loading PIN diode. Full-wave simulations show that the reflection coefficients of the metasurface can dynamically vary within −30dB at 3.4 GHz and 8.2 GHz respectively, which validate the effectiveness of the design.
{"title":"A Multistate Tunable Low-Scattering Metasurface Design with Characteristic Mode Theory","authors":"Zihao Ning, Wenzhao Song, Hongzhan Hong, Mengmeng Li, Dazhi Ding","doi":"10.1109/ICMMT55580.2022.10023398","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10023398","url":null,"abstract":"A multistate tunable low-scattering metasurface is designed with characteristic mode theory (CMT) in this paper. By analyzing the surface currents and mode excitation coefficients of the structure, the value and load position of impedance are guided to achieve a low-scattering design. Furthermore, the metasurface can be switched between different scattering states and operating bands by loading PIN diode. Full-wave simulations show that the reflection coefficients of the metasurface can dynamically vary within −30dB at 3.4 GHz and 8.2 GHz respectively, which validate the effectiveness of the design.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130622718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/ICMMT55580.2022.10022590
Xiao Mengxuan, Hu Taiyang, Li Lei, Shao Xiaolang, Zhang Jinyu, Xue Wen, Xiao Zelong
A basic frequency diverse array(FDA) using linearly increasing frequency offset produces an S-shaped range-angle coupled beampattern, which is limited to apply to radar detection. In this paper, a novel FDA with nonlinear frequency offset and nonlinear multicarrier which are optimized by the Mayfly Algorithm(MA) is proposed. Simulation results demonstrate that, compared with two other dot-shaped beampattern synthesis for FDA, the proposed method has made great improvements in spatial focusing and sidelobe suppression.
{"title":"Frequency Diverse Array Beampattern Synthesis with Joint Optimization of Frequency Offset and Carrier","authors":"Xiao Mengxuan, Hu Taiyang, Li Lei, Shao Xiaolang, Zhang Jinyu, Xue Wen, Xiao Zelong","doi":"10.1109/ICMMT55580.2022.10022590","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10022590","url":null,"abstract":"A basic frequency diverse array(FDA) using linearly increasing frequency offset produces an S-shaped range-angle coupled beampattern, which is limited to apply to radar detection. In this paper, a novel FDA with nonlinear frequency offset and nonlinear multicarrier which are optimized by the Mayfly Algorithm(MA) is proposed. Simulation results demonstrate that, compared with two other dot-shaped beampattern synthesis for FDA, the proposed method has made great improvements in spatial focusing and sidelobe suppression.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123898385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/ICMMT55580.2022.10022765
Zhe Jiang, Jinghui Qiu
Applications of passive millimeter waves (PMMWs), especially PMMW imaging and PMMW radar, are required in medicine, homeland security, communication, and space technology, but constrained by the limited field-of-view (Fo V) of focal plane array (FPA). In this paper, the influence of feed antenna tilt on antenna gain is investigated theoretically, and a forward free-form surface optimization method to expand FoV is proposed, thereby designing a wide-scan MMW focal plane array with a free-form surface reflector, which provides a high antenna gain of 46.5dB. The staggered placement of feed antennas achieves a 3dB effective isotropic radiated power (EIRP) within a relatively large field of view, up to +/-18.7°. The FPA uses a paraboloid-based Zernike freeform reflector that optimizes the illumination of the far field region according to the feed pattern. In this way, we could improve the FoV and increase feed elements of the system without worrying about coupling efficiency between the focus field and single mode feed antenna.
{"title":"A Large Field-of-View Focal Plane Array based on Zernike Freeform Surface","authors":"Zhe Jiang, Jinghui Qiu","doi":"10.1109/ICMMT55580.2022.10022765","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10022765","url":null,"abstract":"Applications of passive millimeter waves (PMMWs), especially PMMW imaging and PMMW radar, are required in medicine, homeland security, communication, and space technology, but constrained by the limited field-of-view (Fo V) of focal plane array (FPA). In this paper, the influence of feed antenna tilt on antenna gain is investigated theoretically, and a forward free-form surface optimization method to expand FoV is proposed, thereby designing a wide-scan MMW focal plane array with a free-form surface reflector, which provides a high antenna gain of 46.5dB. The staggered placement of feed antennas achieves a 3dB effective isotropic radiated power (EIRP) within a relatively large field of view, up to +/-18.7°. The FPA uses a paraboloid-based Zernike freeform reflector that optimizes the illumination of the far field region according to the feed pattern. In this way, we could improve the FoV and increase feed elements of the system without worrying about coupling efficiency between the focus field and single mode feed antenna.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114218609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/ICMMT55580.2022.10022558
Bo Zhou, Xin Huai Wang, Jun Jie Hu, Yin Xu, X. Shi
In this paper, in order to solve the problem of the performance degradation of millimeter wave cavity filters under extreme temperatures, this paper designs a fifth-order cavity filter with a center frequency of 25–27 GHz, and analyzes the environmental temperature caused by the copper millimeter wave cavity filter. Design a new structure that uses the inverse piezoelectric effect of piezoelectric materials to offset the environmental impact through piezoelectric materials. By means of multi-physics coupling, the influence of temperature on the cavity filter is offset. It can be obtained through COMSOL simulation that this structure can offset the influence of high temperature and low temperature on the performance of the filter, and complete temperature compensation, which has great practical significance.
{"title":"A Design of Millimeter-Wave Cavity Filter Based on Multiphysics Analysis","authors":"Bo Zhou, Xin Huai Wang, Jun Jie Hu, Yin Xu, X. Shi","doi":"10.1109/ICMMT55580.2022.10022558","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10022558","url":null,"abstract":"In this paper, in order to solve the problem of the performance degradation of millimeter wave cavity filters under extreme temperatures, this paper designs a fifth-order cavity filter with a center frequency of 25–27 GHz, and analyzes the environmental temperature caused by the copper millimeter wave cavity filter. Design a new structure that uses the inverse piezoelectric effect of piezoelectric materials to offset the environmental impact through piezoelectric materials. By means of multi-physics coupling, the influence of temperature on the cavity filter is offset. It can be obtained through COMSOL simulation that this structure can offset the influence of high temperature and low temperature on the performance of the filter, and complete temperature compensation, which has great practical significance.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114642250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ultra-high frequency (UHF) method is a kind of online monitoring of partial discharge signal. It has the advantages of high sensitivity, strong anti-interference ability, and has been widely used. Therefore, an external composite spiral antenna sensor is designed for partial discharge detection of gas insulated switchgear (GIS). The composite spiral antenna adopts the equiangular spiral antenna and archimedes spiral composite structure, terminal uses the butterfly vibrator loads, the metal back cavity, ultra broadband barron, can satisfy the requirement of the antenna miniaturization. The size of UHF sensor is 120mm $times 90text{mm}times 75text{mm}$, its standing wave ratio is less than 2.5 among 1GHz-1.5GHz. And the gain above 1GHz is greater than 4dB. In the UHF band, it has good detection performance and multi-band selection characteristics.
{"title":"An External UHF Composite Spiral Antenna for Partial Discharge Detection in GIS","authors":"Haozhe Liang, Hongda Lu, Yong Liu, Pengfei Zhen, Xin Lv","doi":"10.1109/ICMMT55580.2022.10023377","DOIUrl":"https://doi.org/10.1109/ICMMT55580.2022.10023377","url":null,"abstract":"The ultra-high frequency (UHF) method is a kind of online monitoring of partial discharge signal. It has the advantages of high sensitivity, strong anti-interference ability, and has been widely used. Therefore, an external composite spiral antenna sensor is designed for partial discharge detection of gas insulated switchgear (GIS). The composite spiral antenna adopts the equiangular spiral antenna and archimedes spiral composite structure, terminal uses the butterfly vibrator loads, the metal back cavity, ultra broadband barron, can satisfy the requirement of the antenna miniaturization. The size of UHF sensor is 120mm $times 90text{mm}times 75text{mm}$, its standing wave ratio is less than 2.5 among 1GHz-1.5GHz. And the gain above 1GHz is greater than 4dB. In the UHF band, it has good detection performance and multi-band selection characteristics.","PeriodicalId":211726,"journal":{"name":"2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT)","volume":"1594 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116504065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：