Pub Date : 2018-08-01DOI: 10.1109/APCAP.2018.8538138
Xiaojun Ying, Y. Liao, Guochang Shi, Yanan Chen, Aixin Chen
This paper presents a novel algorithm -artificial immune algorithm (AIA) which is inspired by the biological artificial immune system (AIS) for optimal problems. It is employed to a micro-strip antenna design for gain improvement and bandwidth extension. Characterized by Fitness-Concentration selection mechanism and Elite Reservation features, the proposed AIA is built up and tested in a searching multiple maximums issue, showing its higher searching efficiency compared with conventional genetic algorithm (GA). Micro-strip antenna being optimized is a $4times 1$ element single-layer array with thin substrate and corner-cut square patches, operating around 2.4 GHz. By adjusting the chamfer size, space between patches, the final antenna array optimized by AIA has a bandwidth improvement of 3.4% and an obvious gain enhancement of about 13dBi.
{"title":"A Novel Artificial Immune Algorithm and Its Application to Micro-strip Antenna Array Design","authors":"Xiaojun Ying, Y. Liao, Guochang Shi, Yanan Chen, Aixin Chen","doi":"10.1109/APCAP.2018.8538138","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538138","url":null,"abstract":"This paper presents a novel algorithm -artificial immune algorithm (AIA) which is inspired by the biological artificial immune system (AIS) for optimal problems. It is employed to a micro-strip antenna design for gain improvement and bandwidth extension. Characterized by Fitness-Concentration selection mechanism and Elite Reservation features, the proposed AIA is built up and tested in a searching multiple maximums issue, showing its higher searching efficiency compared with conventional genetic algorithm (GA). Micro-strip antenna being optimized is a $4times 1$ element single-layer array with thin substrate and corner-cut square patches, operating around 2.4 GHz. By adjusting the chamfer size, space between patches, the final antenna array optimized by AIA has a bandwidth improvement of 3.4% and an obvious gain enhancement of about 13dBi.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"59 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124229622","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538072
Mingming Wang, Dongsheng Li, Ziming Liu, Yijie Gong
Large-scale reflector for compact test range (CTR) is usually obtained by block manufacturing followed by unified assembly alignment. As a consequence, appropriate alignment method is vital for acquiring reflector surfaces with high accuracy. However, periodic oscillation occurs during alignment of reflector panels due to insufficient depth and no isolation of the concrete foundation. To resolve the alignment problem caused by periodic oscillation of the foundation, this paper proposes an iterative self-modified alignment method using a laser tracker, the key to which is how to plan alignment sequence and select appropriate reference points for modifying measurement coordinate system. The method effectively reduces the extra alignment deviation due to periodic oscillation of the foundation, where the loss of accuracy is only 7.9 percent of the theoretical value, while the root mean square of the surface error reduces to 0.041 millimeter. Finally, a microwave amplitude and phase test system based on probe scanning has been established to evaluate electromagnetic performance of the CTR, and the results meet the design requirements.
{"title":"Alignment Method of Reflector Panels for Compact Test Range in Periodic Oscillation Environment","authors":"Mingming Wang, Dongsheng Li, Ziming Liu, Yijie Gong","doi":"10.1109/APCAP.2018.8538072","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538072","url":null,"abstract":"Large-scale reflector for compact test range (CTR) is usually obtained by block manufacturing followed by unified assembly alignment. As a consequence, appropriate alignment method is vital for acquiring reflector surfaces with high accuracy. However, periodic oscillation occurs during alignment of reflector panels due to insufficient depth and no isolation of the concrete foundation. To resolve the alignment problem caused by periodic oscillation of the foundation, this paper proposes an iterative self-modified alignment method using a laser tracker, the key to which is how to plan alignment sequence and select appropriate reference points for modifying measurement coordinate system. The method effectively reduces the extra alignment deviation due to periodic oscillation of the foundation, where the loss of accuracy is only 7.9 percent of the theoretical value, while the root mean square of the surface error reduces to 0.041 millimeter. Finally, a microwave amplitude and phase test system based on probe scanning has been established to evaluate electromagnetic performance of the CTR, and the results meet the design requirements.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125013506","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538204
Zhen-Xing Xia, K. Leung
A gain enhancement method for the rectangular dielectric resonator antenna (RDRA) is studied. A new uniplanar electromagnetic bandgap (EBG) surface is printed around the RDRA. Its reflection coefficient, radiation pattern, and antenna gain are studied and compared with those of a reference DRA without the EBG structure. Simulated results show that the antenna gain can be increased by more than 3.5 dB.
{"title":"Gain Enhancement of Rectangular Dielectric Resonator Antenna Using EBG Surface","authors":"Zhen-Xing Xia, K. Leung","doi":"10.1109/APCAP.2018.8538204","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538204","url":null,"abstract":"A gain enhancement method for the rectangular dielectric resonator antenna (RDRA) is studied. A new uniplanar electromagnetic bandgap (EBG) surface is printed around the RDRA. Its reflection coefficient, radiation pattern, and antenna gain are studied and compared with those of a reference DRA without the EBG structure. Simulated results show that the antenna gain can be increased by more than 3.5 dB.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116446396","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538291
Bi Xiaojun
This paper presents three silicon-based 100 GHz radiometer chips for passive imaging, including a total power radiometer and two types of Dicke radiometers. The total power radiometer consists of a high gain low noise amplifier (LNA) and a high-responsivity detector. Besides the LNA and the detector, the two Dicke radiometers include an additional passive SPDT switch and a proposed SPDT amplifier respectively. The above radiometers are fabricated in two different $0.13 mu mathrm {m}$ SiGe BiCMOS technologies, which feature comparable $f_{mathrm {T}}/ f_{max}$. The measurement results demonstrate a typical LNA gain of 35–45 dB utilizing 4 cascode stages, a typical responsivity of 27.2 kV/W, a typical noise equivalent power of around $2.5,mathrm{pW/surd Hz}$ at 91 GHz. Utilizing the SPDT amplifier, the Dicke radiometer demonstrates a switching loss as small as 0.93 @ 91 GHz, which leads to a noise equivalent temperature difference (NETD) as small as 0.21 K@30 ms.
{"title":"Silicon-Based sub-THz Radiometers for Passive Imaging","authors":"Bi Xiaojun","doi":"10.1109/APCAP.2018.8538291","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538291","url":null,"abstract":"This paper presents three silicon-based 100 GHz radiometer chips for passive imaging, including a total power radiometer and two types of Dicke radiometers. The total power radiometer consists of a high gain low noise amplifier (LNA) and a high-responsivity detector. Besides the LNA and the detector, the two Dicke radiometers include an additional passive SPDT switch and a proposed SPDT amplifier respectively. The above radiometers are fabricated in two different $0.13 mu mathrm {m}$ SiGe BiCMOS technologies, which feature comparable $f_{mathrm {T}}/ f_{max}$. The measurement results demonstrate a typical LNA gain of 35–45 dB utilizing 4 cascode stages, a typical responsivity of 27.2 kV/W, a typical noise equivalent power of around $2.5,mathrm{pW/surd Hz}$ at 91 GHz. Utilizing the SPDT amplifier, the Dicke radiometer demonstrates a switching loss as small as 0.93 @ 91 GHz, which leads to a noise equivalent temperature difference (NETD) as small as 0.21 K@30 ms.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125513697","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538163
Boyu Sima, Ke Chen, Yijun Feng
In this paper, we have designed and fabricated a reflective type 1-bit coding metasurface, which can be used forefciently reducing the backward radar cross section with frequency selective characteristic. Different from conventional diffusion-like metasurfaces, the proposed metasurface only diffuse the scattering wave outside the working frequency band, while at the working frequency it behaves as a mirror surface with specular refection property. Both simulated and experimental results validate that the proposed metasurface has a RCS reduction effect more than 10 dB from 9 GHz to 13.6 GHz and 17 GHz to 20 GHz, while a specular reflection around 15 GHz.
{"title":"Reflective 1-bit Coding Metasurface for Frequency Selective RCS Reduction","authors":"Boyu Sima, Ke Chen, Yijun Feng","doi":"10.1109/APCAP.2018.8538163","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538163","url":null,"abstract":"In this paper, we have designed and fabricated a reflective type 1-bit coding metasurface, which can be used forefciently reducing the backward radar cross section with frequency selective characteristic. Different from conventional diffusion-like metasurfaces, the proposed metasurface only diffuse the scattering wave outside the working frequency band, while at the working frequency it behaves as a mirror surface with specular refection property. Both simulated and experimental results validate that the proposed metasurface has a RCS reduction effect more than 10 dB from 9 GHz to 13.6 GHz and 17 GHz to 20 GHz, while a specular reflection around 15 GHz.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117339626","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538300
Y. She, Y. Kato, S. Kurokawa, J. Hirokawa
Efficiency prediction or loss estimation is important for estimating the performance of the circuits in the millimeter waveband. This report gave the examples of efficiency prediction of the LTCC post-wall waveguide and plane antenna numerically and experimentally at 60 GHz. The uncertainties of the dielectric properties have been carefully measured and considered in the efficiency prediction in the millimeter wave.
{"title":"Examples of Loss Prediction and Measurement of LTCC Circuits Uncertainties of dielectric loss in millimeter waveband","authors":"Y. She, Y. Kato, S. Kurokawa, J. Hirokawa","doi":"10.1109/APCAP.2018.8538300","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538300","url":null,"abstract":"Efficiency prediction or loss estimation is important for estimating the performance of the circuits in the millimeter waveband. This report gave the examples of efficiency prediction of the LTCC post-wall waveguide and plane antenna numerically and experimentally at 60 GHz. The uncertainties of the dielectric properties have been carefully measured and considered in the efficiency prediction in the millimeter wave.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"06 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128781479","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538118
Zeqi Zhu, Xu-ling Lin, X. Ji
For improving the performance of CMOS terahertz detectors, parasitic capacitance reduction technique and new working model are proposed for MOSFET devices. We investigate the influence of source parasitic capacitance and drain-to-source current on the performance of CMOS terahertz detectors and analyze the relationship to the voltage responsivity $(mathrm{R}_{V})$ and noise equivalent power (NEP) of detectors. Experiment on the CMOS detectors with a 650GHz antenna shows the maximum improvement of voltage responsivity can attain to 155% by suppressing gate-source parasitic capacitance. The additional drain current Ids can further increase RV while NEP remains unchanged.
{"title":"Performance Enhancement Of Cmos Terahertz Detector","authors":"Zeqi Zhu, Xu-ling Lin, X. Ji","doi":"10.1109/APCAP.2018.8538118","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538118","url":null,"abstract":"For improving the performance of CMOS terahertz detectors, parasitic capacitance reduction technique and new working model are proposed for MOSFET devices. We investigate the influence of source parasitic capacitance and drain-to-source current on the performance of CMOS terahertz detectors and analyze the relationship to the voltage responsivity $(mathrm{R}_{V})$ and noise equivalent power (NEP) of detectors. Experiment on the CMOS detectors with a 650GHz antenna shows the maximum improvement of voltage responsivity can attain to 155% by suppressing gate-source parasitic capacitance. The additional drain current Ids can further increase RV while NEP remains unchanged.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116685252","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538066
Xianmin Zhang, Jiayu Zheng, Shilie Zheng
The orbital angular momentum (OAM) carrying beams associated with helical wavefronts can be viewed as a complete set of eigen-modes for the electromagnetic waves, thus can be used to realize the structured radio wavefront with desired intensity and phase distribution. The structured radio beam maintains the vorticity and orthogonality of the OAM modes and has a directional gain. The unique characteristics provided by structured radio beam may afford a new solution to radar detection.
{"title":"Structured Radio Beam for Radar Detection","authors":"Xianmin Zhang, Jiayu Zheng, Shilie Zheng","doi":"10.1109/APCAP.2018.8538066","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538066","url":null,"abstract":"The orbital angular momentum (OAM) carrying beams associated with helical wavefronts can be viewed as a complete set of eigen-modes for the electromagnetic waves, thus can be used to realize the structured radio wavefront with desired intensity and phase distribution. The structured radio beam maintains the vorticity and orthogonality of the OAM modes and has a directional gain. The unique characteristics provided by structured radio beam may afford a new solution to radar detection.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117046087","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538266
Xiaonan Zhao, R. Jin, Jun-ping Geng, Han Zhou, Zhengji Liu, Hang Ji, Xiao Du
In this paper, a spoof surface plasmon polariton (SSPP) conical beam antenna is proposed for haze-detecting mobile station. It is composed of a smoothly connected truncated- cone with multilayered toothed structure along the cylindrical bar. And the antenna combines the whip performance and SSPP effect to construct the conical beam. After optimization of PSO, the antenna achieves impedance bandwidth 20% over 320 MHz ~ 525 MHz, the rotation symmetrical beam covers the upper half space and satisfies the air link gain demands to haze-detecting. The maximum size is $0.39lambda ^{star }0.39lambda ^{star }0.55lambda (phi 365mathrm {m}mathrm {m}^{star }mathrm {h}512.9mathrm {m}mathrm {m})$, which is very compact, lightweight, and being suitable for 3D printing.
本文提出了一种用于雾霾探测移动台的欺骗表面等离子体极化子锥形波束天线。它是由一个沿圆柱杆光滑连接的截锥和多层齿状结构组成的。该天线结合了鞭波特性和SSPP效应来构造锥形波束。优化后的天线阻抗带宽达到20% over 320 MHz ~ 525 MHz, the rotation symmetrical beam covers the upper half space and satisfies the air link gain demands to haze-detecting. The maximum size is $0.39lambda ^{star }0.39lambda ^{star }0.55lambda (phi 365mathrm {m}mathrm {m}^{star }mathrm {h}512.9mathrm {m}mathrm {m})$, which is very compact, lightweight, and being suitable for 3D printing.
{"title":"Design of Spoof Surface Plasmon Polariton Conical Beam Antenna Combining Particle Swarm Optimization for Haze-detecting","authors":"Xiaonan Zhao, R. Jin, Jun-ping Geng, Han Zhou, Zhengji Liu, Hang Ji, Xiao Du","doi":"10.1109/APCAP.2018.8538266","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538266","url":null,"abstract":"In this paper, a spoof surface plasmon polariton (SSPP) conical beam antenna is proposed for haze-detecting mobile station. It is composed of a smoothly connected truncated- cone with multilayered toothed structure along the cylindrical bar. And the antenna combines the whip performance and SSPP effect to construct the conical beam. After optimization of PSO, the antenna achieves impedance bandwidth 20% over 320 MHz ~ 525 MHz, the rotation symmetrical beam covers the upper half space and satisfies the air link gain demands to haze-detecting. The maximum size is $0.39lambda ^{star }0.39lambda ^{star }0.55lambda (phi 365mathrm {m}mathrm {m}^{star }mathrm {h}512.9mathrm {m}mathrm {m})$, which is very compact, lightweight, and being suitable for 3D printing.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131936251","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 : 2018-08-01DOI: 10.1109/APCAP.2018.8538120
Zhang Qiang, Z. Zhipeng
In this paper the RCS simulation and measurement of FSS radome are present. A Pyramid or diamond shape Asandwich radome is designed aim to simplify modeling. The FSS are embedded within the skins of A-sandwich wall. The RCS of radome without FSS and with FSS are both calculated by commercial software. The experiment is conducted that shows agreement with simulation in contour. It is also found that the RCS reduction of radome is significant when absorbing structure is applied. It has been demonstrated that it is possible to control the RCS of FSS radome by suitable design and validate simulation.
{"title":"Research on RCS of FSS Radome","authors":"Zhang Qiang, Z. Zhipeng","doi":"10.1109/APCAP.2018.8538120","DOIUrl":"https://doi.org/10.1109/APCAP.2018.8538120","url":null,"abstract":"In this paper the RCS simulation and measurement of FSS radome are present. A Pyramid or diamond shape Asandwich radome is designed aim to simplify modeling. The FSS are embedded within the skins of A-sandwich wall. The RCS of radome without FSS and with FSS are both calculated by commercial software. The experiment is conducted that shows agreement with simulation in contour. It is also found that the RCS reduction of radome is significant when absorbing structure is applied. It has been demonstrated that it is possible to control the RCS of FSS radome by suitable design and validate simulation.","PeriodicalId":198124,"journal":{"name":"2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132023265","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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