Pub Date : 2015-05-17DOI: 10.1109/MWSYM.2015.7166715
K. Thurn, D. Shmakov, Gang Li, S. Max, M. Meinecke, M. Vossiek
In this paper, we introduce a novel concept for primary frequency-modulated continuous-wave (FMCW) radar. The approach is based on a phase locked loop-controlled interlaced chirp sequence (ICS) waveform and, in contrast to basic range-Doppler processing, it enables higher target velocities to be detected. It is thus very suitable for automotive applications. The interlaced ramps in the system are generated by two separate frequency synthesizers. These are combined by an RF switch to suppress transients caused by oscillator overshoot and to avoid incoherencies due to programming times of the phase locked loop (PLL) ICs. A prototype radar system was realized in K-Band. Promising test results bode well for other applications.
{"title":"A novel interlaced chirp sequence radar concept with range-Doppler processing for automotive applications","authors":"K. Thurn, D. Shmakov, Gang Li, S. Max, M. Meinecke, M. Vossiek","doi":"10.1109/MWSYM.2015.7166715","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7166715","url":null,"abstract":"In this paper, we introduce a novel concept for primary frequency-modulated continuous-wave (FMCW) radar. The approach is based on a phase locked loop-controlled interlaced chirp sequence (ICS) waveform and, in contrast to basic range-Doppler processing, it enables higher target velocities to be detected. It is thus very suitable for automotive applications. The interlaced ramps in the system are generated by two separate frequency synthesizers. These are combined by an RF switch to suppress transients caused by oscillator overshoot and to avoid incoherencies due to programming times of the phase locked loop (PLL) ICs. A prototype radar system was realized in K-Band. Promising test results bode well for other applications.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"11 2 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78330244","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7166907
M. Hossain, N. Weimann, M. Lisker, C. Meliani, B. Tillack, V. Krozer, W. Heinrich
This paper presents a 330 GHz hetero-integrated signal source using InP-on-BiCMOS technology. It consists of a fundamental Voltage Controlled Oscillator (VCO) in 0.25 μm BiCMOS technology and a frequency quadrupler in 0.8 μm transferred substrate (TS) InP-HBT technology, which is integrated on top of the BiCMOS MMIC in a wafer-level BCB bonding process. The fundamental VCO operates at 82 GHz and the combined source delivers -12 dBm output power at 328 GHz. To the knowledge of the authors, this is the first hetero-integrated signal source in the frequency range beyond 300 GHz reported so far. It demonstrates the potential of the hetero-integration process for THz frequencies.
{"title":"A 330 GHz hetero-integrated source in InP-on-BiCMOS technology","authors":"M. Hossain, N. Weimann, M. Lisker, C. Meliani, B. Tillack, V. Krozer, W. Heinrich","doi":"10.1109/MWSYM.2015.7166907","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7166907","url":null,"abstract":"This paper presents a 330 GHz hetero-integrated signal source using InP-on-BiCMOS technology. It consists of a fundamental Voltage Controlled Oscillator (VCO) in 0.25 μm BiCMOS technology and a frequency quadrupler in 0.8 μm transferred substrate (TS) InP-HBT technology, which is integrated on top of the BiCMOS MMIC in a wafer-level BCB bonding process. The fundamental VCO operates at 82 GHz and the combined source delivers -12 dBm output power at 328 GHz. To the knowledge of the authors, this is the first hetero-integrated signal source in the frequency range beyond 300 GHz reported so far. It demonstrates the potential of the hetero-integration process for THz frequencies.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"85 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76327180","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7167116
S. Linz, F. Lurz, M. Sporer, S. Lindner, S. Mann, R. Weigel, A. Koelpin
This work introduces a precise measurement setup for displacement analysis in the near field of a tapered slot-line antenna from 0mm up to 20mm distance. Enhanced accuracy is achieved by a dedicated spiral reconstruction algorithm accounting for the near field effects. Moreover, the precision of the system in the micrometer range is guaranteed by four synchronous 24 bit analog-to-digital converters and a decimation factor of 10, leading to an overall update rate of 1 kHz.
{"title":"Ultra-short-range, precise displacement measurement setup with a near field slot-line antenna and a dedicated spiral calibration","authors":"S. Linz, F. Lurz, M. Sporer, S. Lindner, S. Mann, R. Weigel, A. Koelpin","doi":"10.1109/MWSYM.2015.7167116","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7167116","url":null,"abstract":"This work introduces a precise measurement setup for displacement analysis in the near field of a tapered slot-line antenna from 0mm up to 20mm distance. Enhanced accuracy is achieved by a dedicated spiral reconstruction algorithm accounting for the near field effects. Moreover, the precision of the system in the micrometer range is guaranteed by four synchronous 24 bit analog-to-digital converters and a decimation factor of 10, leading to an overall update rate of 1 kHz.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"21 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74814511","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7167086
U. Kim, J. Woo, Sunghwan Park, Y. Kwon
A multiband linear CMOS power amplifier (PA) is developed to cover multiple LTE bands from 800 to 2000 MHz using a single PA core. The single-chain PA is based on a two-stage design using stacked-FET cells, and is designed to support any combinations of low/high dual bands out of five popular 3G/4G bands (Band 1/2/4/5/8). To avoid the performance degradation by covering such a wide bandwidth using a single PA-core, the frequency reconfigurability has been applied to the stacked-FET cells, interstage matching as well as the output matching. To further enhance the linearity and efficiency, a phase-based linearizer is employed and reconfigured according to the operating frequencies. W-CDMA test on the fabricated PA shows adjacent channel leakage ratios (ACLRs) better than -39 dBc up to the rated linear power of 28.5 dBm and power-added efficiencies (PAEs) higher than 40.7% and 46% for high- and low- frequency band groups, respectively. Compared with the dedicated PAs using the same process, PAE degradation is limited to 1.6 ~ 3.3%. To our knowledge, this work is among the best results from the single-chain PAs for 3G/4G mobile applications.
{"title":"A single-chain multiband reconfigurable linear power amplifier in SOI CMOS","authors":"U. Kim, J. Woo, Sunghwan Park, Y. Kwon","doi":"10.1109/MWSYM.2015.7167086","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7167086","url":null,"abstract":"A multiband linear CMOS power amplifier (PA) is developed to cover multiple LTE bands from 800 to 2000 MHz using a single PA core. The single-chain PA is based on a two-stage design using stacked-FET cells, and is designed to support any combinations of low/high dual bands out of five popular 3G/4G bands (Band 1/2/4/5/8). To avoid the performance degradation by covering such a wide bandwidth using a single PA-core, the frequency reconfigurability has been applied to the stacked-FET cells, interstage matching as well as the output matching. To further enhance the linearity and efficiency, a phase-based linearizer is employed and reconfigured according to the operating frequencies. W-CDMA test on the fabricated PA shows adjacent channel leakage ratios (ACLRs) better than -39 dBc up to the rated linear power of 28.5 dBm and power-added efficiencies (PAEs) higher than 40.7% and 46% for high- and low- frequency band groups, respectively. Compared with the dedicated PAs using the same process, PAE degradation is limited to 1.6 ~ 3.3%. To our knowledge, this work is among the best results from the single-chain PAs for 3G/4G mobile applications.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"170 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73150346","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7167017
A. Costanzo, D. Masotti
Wireless power transfer (WPT) is foreseen as a key enabling technology for energy-autonomous wireless sensors, Internet of Things and Device to Device communication. RF energy, either scavenged from the ambient or intentionally provided to a wireless device, can be successfully exploited for autonomously sustaining its operations. In this paper we overview the main aspects to be addressed for a successful design of a far-field WPT system. The end-to-end circuit level co-design of the WPT link is described as the procedure to effectively address the system optimum efficiency. Specific selection of antenna elements and active sub-circuits are analyzed, depending on the power levels involved and on the specific application environment. The base-band design of the power management unit used to dynamically provide the receiver with optimum loading conditions is also analyzed.
{"title":"Wirelessly powering: An enabling technology for zero-power sensors, IoT and D2D communication","authors":"A. Costanzo, D. Masotti","doi":"10.1109/MWSYM.2015.7167017","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7167017","url":null,"abstract":"Wireless power transfer (WPT) is foreseen as a key enabling technology for energy-autonomous wireless sensors, Internet of Things and Device to Device communication. RF energy, either scavenged from the ambient or intentionally provided to a wireless device, can be successfully exploited for autonomously sustaining its operations. In this paper we overview the main aspects to be addressed for a successful design of a far-field WPT system. The end-to-end circuit level co-design of the WPT link is described as the procedure to effectively address the system optimum efficiency. Specific selection of antenna elements and active sub-circuits are analyzed, depending on the power levels involved and on the specific application environment. The base-band design of the power management unit used to dynamically provide the receiver with optimum loading conditions is also analyzed.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"48 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74444079","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7166797
C. Baer, Birk Hattenhorst, C. Schulz, B. Will, I. Rolfes, T. Musch
In this contribution, we present a novel simulation based technique for the investigation of arbitrary dielectric material compositions. The proposed procedure bases on a randomization process in combination with transient 3D electromagnetic simulations and robust signal processing. The comparison to commonly known dielectric mixing rules proves the effectiveness of the automated simulation process. Detailed information on the randomized material modeling, the simulation process as well as the evaluation of the applicability of the proposed method are part of this contribution.
{"title":"Effective permittivity determination of randomized mixed materials using 3D electromagnetic simulations","authors":"C. Baer, Birk Hattenhorst, C. Schulz, B. Will, I. Rolfes, T. Musch","doi":"10.1109/MWSYM.2015.7166797","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7166797","url":null,"abstract":"In this contribution, we present a novel simulation based technique for the investigation of arbitrary dielectric material compositions. The proposed procedure bases on a randomization process in combination with transient 3D electromagnetic simulations and robust signal processing. The comparison to commonly known dielectric mixing rules proves the effectiveness of the automated simulation process. Detailed information on the randomized material modeling, the simulation process as well as the evaluation of the applicability of the proposed method are part of this contribution.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"5 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73394723","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7167076
Arian Rahimi, Y. Yoon
Ultra high quality factor (Q-factor) integrated inductors in K-band are reported where a maximum Q-factor of 55 has been achieved in the frequency band of 18-20 GHz. The proposed structure employs nanometer-thick alternating Cu and Ni multilayers, the so-called Cu/Ni nano-superlattice, for the conductor instead of a conventional thick single-layer Cu or Ag film. The conductor architecture efficiently overpasses the skin effect by cancelling the generated eddy currents inside the conductor allowing the current to flow through the whole volume of the conductor, resulting in the reduction of the resistive loss of the inductor. The inductors are nanomachined and measurement results show the highest Q-factor of an on-wafer K-band inductor reported to the best of the authors' knowledge.
{"title":"High-Q K-band integrated inductors using Cu/Ni nano-superlattice conductors","authors":"Arian Rahimi, Y. Yoon","doi":"10.1109/MWSYM.2015.7167076","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7167076","url":null,"abstract":"Ultra high quality factor (Q-factor) integrated inductors in K-band are reported where a maximum Q-factor of 55 has been achieved in the frequency band of 18-20 GHz. The proposed structure employs nanometer-thick alternating Cu and Ni multilayers, the so-called Cu/Ni nano-superlattice, for the conductor instead of a conventional thick single-layer Cu or Ag film. The conductor architecture efficiently overpasses the skin effect by cancelling the generated eddy currents inside the conductor allowing the current to flow through the whole volume of the conductor, resulting in the reduction of the resistive loss of the inductor. The inductors are nanomachined and measurement results show the highest Q-factor of an on-wafer K-band inductor reported to the best of the authors' knowledge.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"32 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73719814","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7166707
A. Tang, F. Hsiao, Yanghyo Kim, L. Du, Long Kong, G. Virbila, Yen-Cheng Kuan, Choonsup Lee, G. Chattopadhyay, N. Chahat, T. Reck, I. Mehdi, M. Chang
This paper presents a 95 GHz centimeter scale navigation system which allows a unmanned ground vehicle (UGV) or possibly even aerial vehicle (UAV) to navigate through a highly cluttered environment and follow a safe obstacle-free pathway to a desired goal. The navigation system defines multiple pathways using mm-wave base-stations called path generators and then uses a single CMOS SoC containing a receiver, ADC and an FFT processor to detect and navigate these pathways. The demonstrated confined pathway SoC (CP-SoC) occupies 5.4mm2 of silicon area in 65nm technology, and consumes only 199 mW, making it suitable for lightweight payloads associated with UAVs and UGVs.
{"title":"A 95 GHz centimeter scale precision confined pathway system-on-chip navigation processor for autonomous vehicles in 65nm CMOS","authors":"A. Tang, F. Hsiao, Yanghyo Kim, L. Du, Long Kong, G. Virbila, Yen-Cheng Kuan, Choonsup Lee, G. Chattopadhyay, N. Chahat, T. Reck, I. Mehdi, M. Chang","doi":"10.1109/MWSYM.2015.7166707","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7166707","url":null,"abstract":"This paper presents a 95 GHz centimeter scale navigation system which allows a unmanned ground vehicle (UGV) or possibly even aerial vehicle (UAV) to navigate through a highly cluttered environment and follow a safe obstacle-free pathway to a desired goal. The navigation system defines multiple pathways using mm-wave base-stations called path generators and then uses a single CMOS SoC containing a receiver, ADC and an FFT processor to detect and navigate these pathways. The demonstrated confined pathway SoC (CP-SoC) occupies 5.4mm2 of silicon area in 65nm technology, and consumes only 199 mW, making it suitable for lightweight payloads associated with UAVs and UGVs.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"132 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73743065","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7167035
S. Afshar, E. Salimi, K. Braasch, M. Butler, D. Thomson, G. Bridges
We present a multi-frequency dielectrophoresis (DEP) based microfluidic device for characterizing the complex dielectric properties of single micron-sized particles while in flow. The device employs a multi-electrode transmission line sensor coupled to a microwave-interferometer, capable of sub-attofarad sensitivity, for detecting the DEP-induced translation of the particle under study. DEP actuation of the particle at different frequencies - which is related to its dielectric response - is sensed as it travels along the sensor. Characterization of the dielectric response of polystyrene micro-spheres using two frequencies is demonstrated.
{"title":"Multi-frequency DEP cytometer employing a microwave interferometer for the dielectric analysis of micro-particles","authors":"S. Afshar, E. Salimi, K. Braasch, M. Butler, D. Thomson, G. Bridges","doi":"10.1109/MWSYM.2015.7167035","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7167035","url":null,"abstract":"We present a multi-frequency dielectrophoresis (DEP) based microfluidic device for characterizing the complex dielectric properties of single micron-sized particles while in flow. The device employs a multi-electrode transmission line sensor coupled to a microwave-interferometer, capable of sub-attofarad sensitivity, for detecting the DEP-induced translation of the particle under study. DEP actuation of the particle at different frequencies - which is related to its dielectric response - is sensed as it travels along the sensor. Characterization of the dielectric response of polystyrene micro-spheres using two frequencies is demonstrated.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"71 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73905950","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 : 2015-05-17DOI: 10.1109/MWSYM.2015.7167151
V. Radisic, K. Leong, D. Scott, C. Monier, Xiaobing Mei, W. Deal, A. Gutierrez-Aitken
In this work, we describe recent advances in InP HEMT and InP HBT technologies that have led to circuits approaching 1 THz. At lower frequencies, these technologies have demonstrated record performance in terms of noise figure (NF), output power, or power-added efficiency (PAE). On the other hand, CMOS-based technologies are dominating semiconductor industry, because they offer high complexity, yield, and integration density. Recent advances in heterogeneous integration enable the combination of compound semiconductor device technologies with CMOS to create complex, compact, and low weight future systems.
{"title":"Sub-millimeter wave InP technologies and integration techniques","authors":"V. Radisic, K. Leong, D. Scott, C. Monier, Xiaobing Mei, W. Deal, A. Gutierrez-Aitken","doi":"10.1109/MWSYM.2015.7167151","DOIUrl":"https://doi.org/10.1109/MWSYM.2015.7167151","url":null,"abstract":"In this work, we describe recent advances in InP HEMT and InP HBT technologies that have led to circuits approaching 1 THz. At lower frequencies, these technologies have demonstrated record performance in terms of noise figure (NF), output power, or power-added efficiency (PAE). On the other hand, CMOS-based technologies are dominating semiconductor industry, because they offer high complexity, yield, and integration density. Recent advances in heterogeneous integration enable the combination of compound semiconductor device technologies with CMOS to create complex, compact, and low weight future systems.","PeriodicalId":6493,"journal":{"name":"2015 IEEE MTT-S International Microwave Symposium","volume":"22 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2015-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79237127","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：