Pub Date : 2018-09-01DOI: 10.23919/EUMC.2018.8541680
Andrea García-Estellés, Juan José Sánchez Martínez, Ana Cristina Gago-Lancho, Francisco Vázquez-Vázquez
A simple method to improve the gain and axial ratio of cavity-backed spiral antennas at low frequencies is presented. The inclusion of appropriate non-metallic materials in the upper cavity walls allows the design of compact antennas without a significant performance degradation at low frequencies. A two-arm Archimedean spiral antenna is designed and simulated in order to validate this method. The antenna can operate in a wide frequency band from 2 to 18 GHz. The results obtained show a considerable gain and axial ratio improvement at 2 GHz.
{"title":"Compact Cavity-Backed Spiral Antennas with Enhanced Axial Ratio and Gain at Low Frequencies","authors":"Andrea García-Estellés, Juan José Sánchez Martínez, Ana Cristina Gago-Lancho, Francisco Vázquez-Vázquez","doi":"10.23919/EUMC.2018.8541680","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541680","url":null,"abstract":"A simple method to improve the gain and axial ratio of cavity-backed spiral antennas at low frequencies is presented. The inclusion of appropriate non-metallic materials in the upper cavity walls allows the design of compact antennas without a significant performance degradation at low frequencies. A two-arm Archimedean spiral antenna is designed and simulated in order to validate this method. The antenna can operate in a wide frequency band from 2 to 18 GHz. The results obtained show a considerable gain and axial ratio improvement at 2 GHz.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"257 1","pages":"392-395"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76648615","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 : 2018-09-01DOI: 10.23919/EUMC.2018.8541393
F. Distler, J. Schür, M. Vossiek
Due to their outstanding transmission behavior of millimeter wave (mmW) signals at high flexibility, low weight and low costs, dielectric waveguides (DWG) represent a convenient technology for future transmission systems and are well suitable for applications like radar, mmW imaging or high speed communication. As different operating conditions require optimized geometries or materials of the DWGs, it is necessary to provide a flexible and robust measurement system to precisely characterize the transmission properties of DWGs with any cross section geometry. To extract the attenuation and phase constants $alpha$ and $beta$ a multiline de-embedding technique is used. Measurement results are shown in this paper.
{"title":"A Flexible Measurement System for Dielectric Waveguide Characterization at mmW Frequencies","authors":"F. Distler, J. Schür, M. Vossiek","doi":"10.23919/EUMC.2018.8541393","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541393","url":null,"abstract":"Due to their outstanding transmission behavior of millimeter wave (mmW) signals at high flexibility, low weight and low costs, dielectric waveguides (DWG) represent a convenient technology for future transmission systems and are well suitable for applications like radar, mmW imaging or high speed communication. As different operating conditions require optimized geometries or materials of the DWGs, it is necessary to provide a flexible and robust measurement system to precisely characterize the transmission properties of DWGs with any cross section geometry. To extract the attenuation and phase constants $alpha$ and $beta$ a multiline de-embedding technique is used. Measurement results are shown in this paper.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"5 1","pages":"886-889"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75329437","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 : 2018-09-01DOI: 10.23919/EUMC.2018.8541644
A. San Blas, J. C. Melgarejo, V. Boria, M. Guglielmi
In this work, a novel topology for the coaxial excitation of band-pass inductive waveguide filters is presented. The proposed solution, which is based on the use of a new dual-mode resonator, provides us with a very compact design compared to the classical topology of this type of filters. Furthermore, this novel resonator produces a transmission zero in the upper side of the filter pass-band, thus improving the response selectivity. For verification purposes, a compact 5-pole band - pass filter has been successfully designed using a systematic procedure. An equivalent circuit model, based on lumped and distributed elements, is also derived in order to ensure a rigorous design process of the considered filter topology,
{"title":"Novel Solution for the Coaxial Excitation of Inductive Rectangular Waveguide Filters","authors":"A. San Blas, J. C. Melgarejo, V. Boria, M. Guglielmi","doi":"10.23919/EUMC.2018.8541644","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541644","url":null,"abstract":"In this work, a novel topology for the coaxial excitation of band-pass inductive waveguide filters is presented. The proposed solution, which is based on the use of a new dual-mode resonator, provides us with a very compact design compared to the classical topology of this type of filters. Furthermore, this novel resonator produces a transmission zero in the upper side of the filter pass-band, thus improving the response selectivity. For verification purposes, a compact 5-pole band - pass filter has been successfully designed using a systematic procedure. An equivalent circuit model, based on lumped and distributed elements, is also derived in order to ensure a rigorous design process of the considered filter topology,","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"3 1","pages":"89-92"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78473051","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 : 2018-09-01DOI: 10.23919/EUMC.2018.8541360
A. Moulay, T. Djerafi
This paper proposes a four-way power divider and combiner based on Luzzatto power divider (LPD) with optimal isolation network study. New implementation based on vertically installed planar isolator permits to have even more number of power way. The LPD rules are derived from the most popular Wilkinson divider. To overcome the 2-D topology limitation, the vertical planar structure has been exploited to realize a bridge isolator between opposite ports. Measurement results shows more than 20 dB of isolation between each two ports and bandwidth of 40% at the operating frequency of 10 GHz. Lower loss, broader bandwidth and simple structure, makes the proposed design a proper candidate for high isolation applications.
{"title":"Four Way Power Divider and Combiner Based on a Luzzatto Divider Using Vertically Installed Planar Bridge Isolator","authors":"A. Moulay, T. Djerafi","doi":"10.23919/EUMC.2018.8541360","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541360","url":null,"abstract":"This paper proposes a four-way power divider and combiner based on Luzzatto power divider (LPD) with optimal isolation network study. New implementation based on vertically installed planar isolator permits to have even more number of power way. The LPD rules are derived from the most popular Wilkinson divider. To overcome the 2-D topology limitation, the vertical planar structure has been exploited to realize a bridge isolator between opposite ports. Measurement results shows more than 20 dB of isolation between each two ports and bandwidth of 40% at the operating frequency of 10 GHz. Lower loss, broader bandwidth and simple structure, makes the proposed design a proper candidate for high isolation applications.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"23 1","pages":"624-627"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78486769","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 : 2018-09-01DOI: 10.23919/EUMIC.2018.8539959
C. V. Vangerow, Daniel Stracke, D. Kissinger, T. Zwick
In this work the design of variable gain amplifiers using the distributed amplifier topology with capacitive division is explored. The effects of the capacitive division technique on gain, line attenuation and bandwidth of the amplifier in different bias states are analyzed by means of circuit simulations and theoretical investigations. The designed 3-stage circuit shows a gain range from −0.1 to 11.9 dB at a bandwidth of at least 1.2 − 83 GHz over all measured gain states. At maximum gain the upper 3dB frequency exceeds 110 GHz. The circuit fabricated in a 130 nm SiGe BiCMOS technology has a chip area of 0.4 mm2and a power consumption of 72 mW at the maximum gain state.
{"title":"Variable Gain Distributed Amplifier with Capacitive Division","authors":"C. V. Vangerow, Daniel Stracke, D. Kissinger, T. Zwick","doi":"10.23919/EUMIC.2018.8539959","DOIUrl":"https://doi.org/10.23919/EUMIC.2018.8539959","url":null,"abstract":"In this work the design of variable gain amplifiers using the distributed amplifier topology with capacitive division is explored. The effects of the capacitive division technique on gain, line attenuation and bandwidth of the amplifier in different bias states are analyzed by means of circuit simulations and theoretical investigations. The designed 3-stage circuit shows a gain range from −0.1 to 11.9 dB at a bandwidth of at least 1.2 − 83 GHz over all measured gain states. At maximum gain the upper 3dB frequency exceeds 110 GHz. The circuit fabricated in a 130 nm SiGe BiCMOS technology has a chip area of 0.4 mm2and a power consumption of 72 mW at the maximum gain state.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"2 1","pages":"1249-1252"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74883096","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 : 2018-09-01DOI: 10.23919/EUMC.2018.8541641
T. Ross, Sam Tiller, K. Ansari, Morris Repeta
A 6-bit phase shifter operating at E-band (71 GHz to 76 GHz) is presented. The differential phase shifter is based on a vector modulator topology, using an accurate variable attenuator to achieve variable gain in the I and Q branches. The accuracy is achieved using combination of a feedback control circuit and a replica circuit. Implemented in a 55 nm BiCMOS technology, the phase shifter measures $pmb{930} mu mathbf{m}times mathbf{410} mu mathbf{m} (mathbf{1965} mu mathbf{m}times mathbf{1080} mu mathbf{m}$ including test baluns and pads). The circuit achieves an RMS phase error of 2.1° and an RMS amplitude error of 0.36 dB over the band of interest.
提出了一种工作在e波段(71 GHz ~ 76 GHz)的6位移相器。差分移相器基于矢量调制器拓扑，使用精确的可变衰减器来实现I和Q支路的可变增益。采用反馈控制电路和复制电路相结合的方法实现了精度。该移相器采用55纳米BiCMOS技术实现，测量$pmb{930} mu mathbf{m} mathbf{m}次mathbf{410} mu mathbf{m} (mathbf{1965} mu mathbf{m} mu mathbf{m}次mathbf{1080} mu mathbf{m}$，包括测试平衡器和pad)。该电路在感兴趣的频带上实现了相位误差的均方根为2.1°，幅度误差的均方根为0.36 dB。
{"title":"A 6-bit Phase Shifter at E-band Using a Feedback-Controlled Variable Attenuator","authors":"T. Ross, Sam Tiller, K. Ansari, Morris Repeta","doi":"10.23919/EUMC.2018.8541641","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541641","url":null,"abstract":"A 6-bit phase shifter operating at E-band (71 GHz to 76 GHz) is presented. The differential phase shifter is based on a vector modulator topology, using an accurate variable attenuator to achieve variable gain in the I and Q branches. The accuracy is achieved using combination of a feedback control circuit and a replica circuit. Implemented in a 55 nm BiCMOS technology, the phase shifter measures $pmb{930} mu mathbf{m}times mathbf{410} mu mathbf{m} (mathbf{1965} mu mathbf{m}times mathbf{1080} mu mathbf{m}$ including test baluns and pads). The circuit achieves an RMS phase error of 2.1° and an RMS amplitude error of 0.36 dB over the band of interest.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"12 1","pages":"800-803"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74990139","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 : 2018-09-01DOI: 10.23919/EUMC.2018.8541362
Alejandro Pons-Abenza, Alejandro Álvarez Melcón, F. Quesada-Pereira, Lara Arche-Andradas
In this work, a refinement of the classical coupled-cavity filter design technique is presented. This refinement consists of a central frequency correction when calculating inter-resonator cavity couplings. The correction introduced is specially critical when 3D shapings are applied to empty cavities, since both resonators and couplings become more dispersive, and frequency tuning is harder due to an increased sensitivity with the resonator geometry. To validate the design approach, a filter design with shaped cavities is realised, where it can be seen that the traditional design technique leads to a starting point which is significantly far from the target specifications. However, the use of the new technique increases the accuracy of its initial response, allowing a simpler final optimization process. The technique presented can have big impact in the efficient design of future filter structures, where 3D shapings are applied to improve performances.
{"title":"Frequency Correction Design Technique for Additive Manufactured Cavity Filters","authors":"Alejandro Pons-Abenza, Alejandro Álvarez Melcón, F. Quesada-Pereira, Lara Arche-Andradas","doi":"10.23919/EUMC.2018.8541362","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541362","url":null,"abstract":"In this work, a refinement of the classical coupled-cavity filter design technique is presented. This refinement consists of a central frequency correction when calculating inter-resonator cavity couplings. The correction introduced is specially critical when 3D shapings are applied to empty cavities, since both resonators and couplings become more dispersive, and frequency tuning is harder due to an increased sensitivity with the resonator geometry. To validate the design approach, a filter design with shaped cavities is realised, where it can be seen that the traditional design technique leads to a starting point which is significantly far from the target specifications. However, the use of the new technique increases the accuracy of its initial response, allowing a simpler final optimization process. The technique presented can have big impact in the efficient design of future filter structures, where 3D shapings are applied to improve performances.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"21 1","pages":"288-291"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75275312","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 : 2018-09-01DOI: 10.23919/EUMIC.2018.8539949
K. Ansari, T. Ross, Morris Repeta
In this paper we present a programmable variable-gain amplifier (VGA) for a 5G demonstration system at E-band. The proposed VGA consists of a common-base amplifier and a variable loss attenuator controlled by a novel programmable feedback circuit. The attenuator is based on a differential π network and it covers 12 dB of range with a 0.5 dB step size. The circuit is implemented in a 55 nm BiCMOS technology and it achieves maximum gain of 4.8 dB and worst case RMS phase error of 2.6° over 71 GHz − 76 GHz. The total power consumption of our design is 18.4 mW from a 1.6 V supply voltage.
{"title":"An E-band Variable-Gain Amplifier Using a Programmable Attenuator","authors":"K. Ansari, T. Ross, Morris Repeta","doi":"10.23919/EUMIC.2018.8539949","DOIUrl":"https://doi.org/10.23919/EUMIC.2018.8539949","url":null,"abstract":"In this paper we present a programmable variable-gain amplifier (VGA) for a 5G demonstration system at E-band. The proposed VGA consists of a common-base amplifier and a variable loss attenuator controlled by a novel programmable feedback circuit. The attenuator is based on a differential π network and it covers 12 dB of range with a 0.5 dB step size. The circuit is implemented in a 55 nm BiCMOS technology and it achieves maximum gain of 4.8 dB and worst case RMS phase error of 2.6° over 71 GHz − 76 GHz. The total power consumption of our design is 18.4 mW from a 1.6 V supply voltage.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"194 1","pages":"1289-1292"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72848331","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 : 2018-09-01DOI: 10.23919/EUMC.2018.8541559
M. Pinto, L. Marzall, Andrea Ashley, D. Psychogiou, Z. Popovic
A modeling approach for the design of microstrip ferrite circulators is presented and validated on several examples using the same commercially-available ferrite disk. A baseline narrowband 4.2S-GHz microstrip circulator is first demonstrated with a commercial 4.97-mm radius ferrite disk operated in saturation and below the ferromagnetic resonance. The non-uniform DC magnetic field distributions of a cylindrical permanent magnet is taken into accout by spatial discretization of the ferrite properties in full-wave simulations. Several design parameters are shown to affect the frequency response; the ferrite thickness relative the microstrip substrate thickness shifts the operating frequency, while external matching networks can increase the fractional bandwidth from 10% up 40%. Another degree of freedom is the applied DC magnetic field, which can be reduced to set the ferrite operation below the ferromagnetic resonance with significant miniaturization of the overall device, as demonstrated with a 1.6-GHz circulator designed with the same 4.97-mm radius ferrite disk, resulting in an almost factor of 3 reduction in linear electrical size.
{"title":"Design-Oriented Modelling of Microstrip Ferrite Circulators","authors":"M. Pinto, L. Marzall, Andrea Ashley, D. Psychogiou, Z. Popovic","doi":"10.23919/EUMC.2018.8541559","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541559","url":null,"abstract":"A modeling approach for the design of microstrip ferrite circulators is presented and validated on several examples using the same commercially-available ferrite disk. A baseline narrowband 4.2S-GHz microstrip circulator is first demonstrated with a commercial 4.97-mm radius ferrite disk operated in saturation and below the ferromagnetic resonance. The non-uniform DC magnetic field distributions of a cylindrical permanent magnet is taken into accout by spatial discretization of the ferrite properties in full-wave simulations. Several design parameters are shown to affect the frequency response; the ferrite thickness relative the microstrip substrate thickness shifts the operating frequency, while external matching networks can increase the fractional bandwidth from 10% up 40%. Another degree of freedom is the applied DC magnetic field, which can be reduced to set the ferrite operation below the ferromagnetic resonance with significant miniaturization of the overall device, as demonstrated with a 1.6-GHz circulator designed with the same 4.97-mm radius ferrite disk, resulting in an almost factor of 3 reduction in linear electrical size.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"53 1","pages":"215-218"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79238465","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 new bandpass three-dimensional frequency-selective surface (3-D FSS) based on the square coaxial waveguide (SCW) with wide stopband is proposed. By utilizing parallel-plate waveguide (PPW) as foundation of one propagation path in the unit cell, two transmission poles can be generated, resulting in a passband. Multiple transmission zeros are obtained by counteraction between paths based on SCWs and reflection in all paths. For this property, a wide stopband is generated for good frequency selectivity. The E-field analysis is presented to offer operating principle of the proposed 3-D FSS. The simulated results exhibit high frequency selectivity, dual polarizations and stable response characteristics under a variation of the incidence angle.
{"title":"Three-Dimensional Frequency Selective Surface with Multiple Transmission Zeros for Wide Stopband","authors":"Jianping Zhu, Zhenyong Yu, Cheng Wang, Cheng Huang, Wanchun Tang","doi":"10.23919/EUMC.2018.8541790","DOIUrl":"https://doi.org/10.23919/EUMC.2018.8541790","url":null,"abstract":"A new bandpass three-dimensional frequency-selective surface (3-D FSS) based on the square coaxial waveguide (SCW) with wide stopband is proposed. By utilizing parallel-plate waveguide (PPW) as foundation of one propagation path in the unit cell, two transmission poles can be generated, resulting in a passband. Multiple transmission zeros are obtained by counteraction between paths based on SCWs and reflection in all paths. For this property, a wide stopband is generated for good frequency selectivity. The E-field analysis is presented to offer operating principle of the proposed 3-D FSS. The simulated results exhibit high frequency selectivity, dual polarizations and stable response characteristics under a variation of the incidence angle.","PeriodicalId":6472,"journal":{"name":"2018 48th European Microwave Conference (EuMC)","volume":"26 1","pages":"61-64"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84254137","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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