Pub Date : 2011-06-05DOI: 10.1109/MWSYM.2011.5972685
Marc J. Franco, D. Dening
In a wireless communication system, a good impedance match between the transmitter and the antenna is essential in order to achieve power efficient operation and maximize the effective radiated power (ERP). In portable scenarios, the antenna impedance is usually subject to wide variations, mostly due to its interaction with objects in the near field. This paper presents a miniature reconfigurable matching network that utilizes a novel circuit topology that minimizes insertion loss due to switch resistance and provides a wide range of impedance match over a bandwidth that exceeds one octave. The network can be implemented in a very small area, which makes it attractive for portable radios. Experimental results are provided for a unit designed for the military UHF satellite communication band that occupies the 220 to 450 MHz spectrum.
{"title":"Broadband reconfigurable matching network of reduced dimensions for the UHF military satellite communication band","authors":"Marc J. Franco, D. Dening","doi":"10.1109/MWSYM.2011.5972685","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972685","url":null,"abstract":"In a wireless communication system, a good impedance match between the transmitter and the antenna is essential in order to achieve power efficient operation and maximize the effective radiated power (ERP). In portable scenarios, the antenna impedance is usually subject to wide variations, mostly due to its interaction with objects in the near field. This paper presents a miniature reconfigurable matching network that utilizes a novel circuit topology that minimizes insertion loss due to switch resistance and provides a wide range of impedance match over a bandwidth that exceeds one octave. The network can be implemented in a very small area, which makes it attractive for portable radios. Experimental results are provided for a unit designed for the military UHF satellite communication band that occupies the 220 to 450 MHz spectrum.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128883946","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972636
R. Simons, E. Wintucky, D. Landon, Jun Y. Sun, J. Winn, S. Laraway, William K. McIntire, J. Metz, F. J. Smith
The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz, output power of 200 watts and efficiency greater than 60%. The modem and the TWTA together enabled an unprecedented data rate at 20 Gbps with low BER of 10−9. The presented results include a plot of the received waveform constellation, BER vs. Eb/N0 and implementation loss for each of the modulation types tested. The above results when included in an RF link budget analysis show that NASA's payload data rate can be increased by an order of magnitude (>10X) over current state-of-practice, limited only by the spacecraft EIRP, ground receiver G/T, range, and available spectrum or bandwidth.
{"title":"Demonstration of multi-Gbps data rates at Ka-band using software-defined modem and broadband high power amplifier for space communications","authors":"R. Simons, E. Wintucky, D. Landon, Jun Y. Sun, J. Winn, S. Laraway, William K. McIntire, J. Metz, F. J. Smith","doi":"10.1109/MWSYM.2011.5972636","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972636","url":null,"abstract":"The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz, output power of 200 watts and efficiency greater than 60%. The modem and the TWTA together enabled an unprecedented data rate at 20 Gbps with low BER of 10−9. The presented results include a plot of the received waveform constellation, BER vs. Eb/N0 and implementation loss for each of the modulation types tested. The above results when included in an RF link budget analysis show that NASA's payload data rate can be increased by an order of magnitude (>10X) over current state-of-practice, limited only by the spacecraft EIRP, ground receiver G/T, range, and available spectrum or bandwidth.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"187 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132488847","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972908
P. Staecker, W. Delaney, A. Gopinath, W. Gelnovatch, D. Mcquiddy, D. Sudbury, A. Sudbury, E. Cohen, W. G. Lyons, M. Gouker
The IEEE MTT Society lost an esteemed colleague and friend, Roger W. Sudbury, on 22 August 2010. We celebrate Roger's life, wisdom, fellowship, and energy through a series of talks in this session that cover Roger's human relationships and contributions to the MTT Society and MIT Lincoln Laboratory, his contributions to the field of gallium arsenide (GaAs) microwave and millimeter-wave monolithic integrated circuits (MMICs), his contributions to the beginnings of phased array antennas based on MMICs, and delve into Roger's family background and origins.
2010年8月22日，IEEE MTT协会失去了一位受人尊敬的同事和朋友，Roger W. Sudbury。我们庆祝罗杰的生活，智慧，奖学金和能量通过一系列的会谈在这个会议上涵盖罗杰的人际关系和贡献的MTT协会和麻省理工学院林肯实验室，他对砷化镓(GaAs)微波和毫米波单片集成电路(mmic)领域的贡献，他对基于mmic相控阵天线的开端的贡献，并深入研究罗杰的家庭背景和起源。
{"title":"IMS2011 memorial session for Roger W. Sudbury","authors":"P. Staecker, W. Delaney, A. Gopinath, W. Gelnovatch, D. Mcquiddy, D. Sudbury, A. Sudbury, E. Cohen, W. G. Lyons, M. Gouker","doi":"10.1109/MWSYM.2011.5972908","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972908","url":null,"abstract":"The IEEE MTT Society lost an esteemed colleague and friend, Roger W. Sudbury, on 22 August 2010. We celebrate Roger's life, wisdom, fellowship, and energy through a series of talks in this session that cover Roger's human relationships and contributions to the MTT Society and MIT Lincoln Laboratory, his contributions to the field of gallium arsenide (GaAs) microwave and millimeter-wave monolithic integrated circuits (MMICs), his contributions to the beginnings of phased array antennas based on MMICs, and delve into Roger's family background and origins.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"357 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132995220","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972839
J. P. Everett, M. J. Kearney, H. Rueda, Eric M. Johnson, P. Aaen, J. Wood, C. Snowden
A new quasi-two-dimensional (Q2D) model is described for microwave laterally diffused MOS (LDMOS) power transistors. A set of one-dimensional energy transport equations are solved across a two-dimensional cross-section in a “current-driven” form. This process-oriented nonlinear model accounts for thermal effects, avalanche breakdown and gate conduction. It accurately predicts DC and microwave characteristics as demonstrated by comparison with measured DC characteristics, transconductance, forward gain, S21, and large-signal gate and drain charges for a LDMOS transistor. The model is fast, taking less than 30 ms to extract a 50 point DC IDS-VDS characteristic and less than 5 ms to produce S-parameters at a single frequency.
{"title":"Fast physical models for Si LDMOS power transistor characterization","authors":"J. P. Everett, M. J. Kearney, H. Rueda, Eric M. Johnson, P. Aaen, J. Wood, C. Snowden","doi":"10.1109/MWSYM.2011.5972839","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972839","url":null,"abstract":"A new quasi-two-dimensional (Q2D) model is described for microwave laterally diffused MOS (LDMOS) power transistors. A set of one-dimensional energy transport equations are solved across a two-dimensional cross-section in a “current-driven” form. This process-oriented nonlinear model accounts for thermal effects, avalanche breakdown and gate conduction. It accurately predicts DC and microwave characteristics as demonstrated by comparison with measured DC characteristics, transconductance, forward gain, S21, and large-signal gate and drain charges for a LDMOS transistor. The model is fast, taking less than 30 ms to extract a 50 point DC IDS-VDS characteristic and less than 5 ms to produce S-parameters at a single frequency.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130842024","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972581
Zhenyu Zhang, K. Wu, Y. Wei
This paper presents a broadband fixed delay compensation phase shifter that makes use of non-radiating longitudinal slots in the broad wall of a substrate integrated waveguide. The design concept is built up on the difference of propagation constants of TE10 mode and quasi-TEM mode, which are the fundamental modes of substrate integrated waveguide and slotted substrate integrated waveguide in the common guided-wave structure, respectively. The proposed method is then validated by both theory and experiments. In this work, a 90 degree phase shifter is designed and implemented over a broad bandwidth from 21 GHz to 28 GHz. Measured results agree well with simulated results. It is shown that our proposed phase shifter has features of wideband, low insertion loss, and easy to fabricate.
{"title":"Broadband delay compensation phase shifter using slotted substrate integrated waveguide structure","authors":"Zhenyu Zhang, K. Wu, Y. Wei","doi":"10.1109/MWSYM.2011.5972581","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972581","url":null,"abstract":"This paper presents a broadband fixed delay compensation phase shifter that makes use of non-radiating longitudinal slots in the broad wall of a substrate integrated waveguide. The design concept is built up on the difference of propagation constants of TE10 mode and quasi-TEM mode, which are the fundamental modes of substrate integrated waveguide and slotted substrate integrated waveguide in the common guided-wave structure, respectively. The proposed method is then validated by both theory and experiments. In this work, a 90 degree phase shifter is designed and implemented over a broad bandwidth from 21 GHz to 28 GHz. Measured results agree well with simulated results. It is shown that our proposed phase shifter has features of wideband, low insertion loss, and easy to fabricate.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130918492","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972592
K. Baur, M. Mayer, T. Binzer, T. Walter
With the rapid development of highly integrated 77 GHz SiGe-Radar-MMICs, cost effective and reliable radar systems are feasible to significantly increase driving safety in all vehicle classes. New functions have to be implemented in these sensors to fulfill the demanding requirements in future advanced driver assistance systems. One criterion will be the exact measurement of angles in the azimuth and also in the elevation plane. A beamforming concept for angular measurements in both directions with one single sensor, using a combination of series fed arrays and a cylindrical dielectric lens, is presented in this paper.
{"title":"Beamforming concepts for angular measurements in azimuth and elevation with 77 GHz lens based radar sensors","authors":"K. Baur, M. Mayer, T. Binzer, T. Walter","doi":"10.1109/MWSYM.2011.5972592","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972592","url":null,"abstract":"With the rapid development of highly integrated 77 GHz SiGe-Radar-MMICs, cost effective and reliable radar systems are feasible to significantly increase driving safety in all vehicle classes. New functions have to be implemented in these sensors to fulfill the demanding requirements in future advanced driver assistance systems. One criterion will be the exact measurement of angles in the azimuth and also in the elevation plane. A beamforming concept for angular measurements in both directions with one single sensor, using a combination of series fed arrays and a cylindrical dielectric lens, is presented in this paper.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130931142","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972690
M. Granger-Jones, B. Nelson, E. Franzwa
In this paper we introduce a novel design technique for broadband high dynamic range absorptive voltage controlled attenuators (VCA) on SOI CMOS. The VCA design is based on the classical passive FET ‘Pi’ and ‘Tee’ attenuator structures but uses stacked FET techniques to dramatically improve the signal handling capability. The VCA has >30dB attenuation range over a frequency band from DC to > 5GHz and achieves an IIP3 of > +47dBm over the entire analog control range. The use of a stacked FET structure evenly distributes the RF signal across ‘N’ FET devices thus reducing the 3rd order distortion generated by each individual FET. The reduction in distortion gained is directly proportional to the degree of stacking used.
{"title":"A broadband high dynamic range voltage controlled attenuator MMIC with IIP3 > +47dBm over entire 30dB analog control range","authors":"M. Granger-Jones, B. Nelson, E. Franzwa","doi":"10.1109/MWSYM.2011.5972690","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972690","url":null,"abstract":"In this paper we introduce a novel design technique for broadband high dynamic range absorptive voltage controlled attenuators (VCA) on SOI CMOS. The VCA design is based on the classical passive FET ‘Pi’ and ‘Tee’ attenuator structures but uses stacked FET techniques to dramatically improve the signal handling capability. The VCA has >30dB attenuation range over a frequency band from DC to > 5GHz and achieves an IIP3 of > +47dBm over the entire analog control range. The use of a stacked FET structure evenly distributes the RF signal across ‘N’ FET devices thus reducing the 3rd order distortion generated by each individual FET. The reduction in distortion gained is directly proportional to the degree of stacking used.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127909957","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972841
J. Zhu, D. Jiao
State-of-the-art methods for solving the low-frequency breakdown problem of full-wave solvers rely on low-frequency approximations, the accuracy of which is a great concern. A rigorous method is developed in this work to fundamentally eliminate the low frequency breakdown problem for full-wave finite-element based analysis of general 3-D problems involving inhomogeneous lossy dielectrics and non-ideal conductors. In this method, the frequency dependence of the solution to Maxwell's equations is explicitly derived from DC to any high frequency. The rigor of the proposed method has been validated by the analysis of realistic on-chip circuits at frequencies as low as DC. Moreover, the proposed method is applicable to both low and high frequencies, and hence constituting a universal solution to Maxwell's equations in a full electromagnetic spectrum.
{"title":"A rigorous solution to the low-frequency breakdown in full-wave finite-element-based analysis of general problems involving inhomogeneous lossy dielectrics and non-ideal conductors","authors":"J. Zhu, D. Jiao","doi":"10.1109/MWSYM.2011.5972841","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972841","url":null,"abstract":"State-of-the-art methods for solving the low-frequency breakdown problem of full-wave solvers rely on low-frequency approximations, the accuracy of which is a great concern. A rigorous method is developed in this work to fundamentally eliminate the low frequency breakdown problem for full-wave finite-element based analysis of general 3-D problems involving inhomogeneous lossy dielectrics and non-ideal conductors. In this method, the frequency dependence of the solution to Maxwell's equations is explicitly derived from DC to any high frequency. The rigor of the proposed method has been validated by the analysis of realistic on-chip circuits at frequencies as low as DC. Moreover, the proposed method is applicable to both low and high frequencies, and hence constituting a universal solution to Maxwell's equations in a full electromagnetic spectrum.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126642278","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5973164
Yu-Ming Lin, K. Jenkins, J. Ott, C. Dimitrakopoulos, D. Farmer, Yanqing Wu, A. Grill, P. Avouris
High-performance graphene field-effect transistors are fabricated on two-inch graphene-on-SiC wafers. Epitaxial graphene was synthesized on SiC wafers by thermal annealing to form one to two layers of graphene. The graphene transistors possess high current density of > 1mA/µm, and a cutoff frequency of 170 GHz is achieved for graphene FETs with a gate length of 90 nm. These results unravel the great potential of graphene for future RF applications.
{"title":"Electrical characterization of wafer-scale epitaxial graphene and its RF applications","authors":"Yu-Ming Lin, K. Jenkins, J. Ott, C. Dimitrakopoulos, D. Farmer, Yanqing Wu, A. Grill, P. Avouris","doi":"10.1109/MWSYM.2011.5973164","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5973164","url":null,"abstract":"High-performance graphene field-effect transistors are fabricated on two-inch graphene-on-SiC wafers. Epitaxial graphene was synthesized on SiC wafers by thermal annealing to form one to two layers of graphene. The graphene transistors possess high current density of > 1mA/µm, and a cutoff frequency of 170 GHz is achieved for graphene FETs with a gate length of 90 nm. These results unravel the great potential of graphene for future RF applications.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123300029","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 : 2011-06-05DOI: 10.1109/MWSYM.2011.5972835
W. Sahyoun, J. Duchamp, P. Benech
Vector Network Analyzer is considered as the classical characterization instrument for RF-devices but it requires time, equipments and increases the cost of tested equipments. A new method is presented and suggested for industrial test of microwave devices. This procedure is based on EVM system-parameter linked to transmission S-parameter. The procedure of the test is easier and six times faster than VNA test. A single value of EVM allows knowing the functionality of the device and few points describe the RF-device characteristics. First tests were done on Butterworth filters of different orders.
{"title":"Industrial combining RF and system test of microwave devices using QPSK modulation","authors":"W. Sahyoun, J. Duchamp, P. Benech","doi":"10.1109/MWSYM.2011.5972835","DOIUrl":"https://doi.org/10.1109/MWSYM.2011.5972835","url":null,"abstract":"Vector Network Analyzer is considered as the classical characterization instrument for RF-devices but it requires time, equipments and increases the cost of tested equipments. A new method is presented and suggested for industrial test of microwave devices. This procedure is based on EVM system-parameter linked to transmission S-parameter. The procedure of the test is easier and six times faster than VNA test. A single value of EVM allows knowing the functionality of the device and few points describe the RF-device characteristics. First tests were done on Butterworth filters of different orders.","PeriodicalId":294862,"journal":{"name":"2011 IEEE MTT-S International Microwave Symposium","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126433092","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}
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