Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9977843
Shenghan Wang, Lei Zhang, Kaiqiang Zhu, Houjun Sun
A multi-band circularly polarized shared-aperture antenna is designed in this paper. The antenna covers five Bei-Dou Navigation Satellite System (BDS) bands and uses a stacked antenna structure. The coaxial lines run through the stack antenna structure to feed the antenna. The influence of the coaxial lines on the resonance of the bottom two-layer patch antenna is eliminated by introducing the isolation column structure. The simulation results of impedance bandwidth $(vert mathrm{S}11vert leq 15mathbf{dB})$ and axial beamwidth meet the design criteria. This kind of antenna could be widely used in satellite communication.
{"title":"Multi-band Shared Aperture Circularly Polarized Antenna With Metal Isolation Columns","authors":"Shenghan Wang, Lei Zhang, Kaiqiang Zhu, Houjun Sun","doi":"10.1109/IWS55252.2022.9977843","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9977843","url":null,"abstract":"A multi-band circularly polarized shared-aperture antenna is designed in this paper. The antenna covers five Bei-Dou Navigation Satellite System (BDS) bands and uses a stacked antenna structure. The coaxial lines run through the stack antenna structure to feed the antenna. The influence of the coaxial lines on the resonance of the bottom two-layer patch antenna is eliminated by introducing the isolation column structure. The simulation results of impedance bandwidth $(vert mathrm{S}11vert leq 15mathbf{dB})$ and axial beamwidth meet the design criteria. This kind of antenna could be widely used in satellite communication.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129187706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9977702
Qinwei Ji, Long Zhang, Jinfeng Zhang, Yaling Chen, Chunxu Mao, Yejun He
A $1.5mathbf{mm}times 28mathbf{mm}$ patch leaky-wave antenna (P-LWA) with a high gain and a large beamwidth in H-plane is proposed for 77GHz automotive radars. Four slots were etched on the driven patch to satisfy the beamwidth requirement in H-plane, which acts as the array element. The simulation results show that the proposed antenna can achieve an impedance bandwidth of 1.3% (76-77GHz) and a maximum realized gain of 15.23dBi. Besides, the proposed antenna can offere an HPBW greater than 118.07° in the H-plane.
{"title":"A 77 GHz Series-fed Leaky-Wave Antenna for Automotive Radar System","authors":"Qinwei Ji, Long Zhang, Jinfeng Zhang, Yaling Chen, Chunxu Mao, Yejun He","doi":"10.1109/IWS55252.2022.9977702","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9977702","url":null,"abstract":"A $1.5mathbf{mm}times 28mathbf{mm}$ patch leaky-wave antenna (P-LWA) with a high gain and a large beamwidth in H-plane is proposed for 77GHz automotive radars. Four slots were etched on the driven patch to satisfy the beamwidth requirement in H-plane, which acts as the array element. The simulation results show that the proposed antenna can achieve an impedance bandwidth of 1.3% (76-77GHz) and a maximum realized gain of 15.23dBi. Besides, the proposed antenna can offere an HPBW greater than 118.07° in the H-plane.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125426891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9977630
Xie He, Qiang Zhou, Lei Zhu, Zhihu Wei, Zhang Chen
To reduce the complex implementation of existing spectrum aliasing-free all-digital radio frequency digital pulse width modulation (RF-PWM) in engineering, a novel RF-PWM all-digital transmitter (ADTx) architecture using sine wave as the reference signal is presented. Four pairs of mutually orthogonal sine wave groups are used as the reference signals of the I and Q quadrature differential PWM units respectively, delta-sigma modulator and digital predistortion are used to suppress modulation noise and spectral aliasing. As a result, alias-free pulse coding can be realized, and the even harmonic components are also suppressed. The feasibility of this novel RF-PWM ADTx is demonstrated, and the system performance is verified by Q PSK and 16QAM signals. Simulation and measurement results show that when compared with the existing RF-PWM ADTx which uses triangular wave as the reference signal, the in-band signal quality and modulation performance of the proposed scheme is similar, but the complexity is much lower.
{"title":"A Spectrum Aliasing-Free All Digital RF -PWM Transmitter Using Sine Wave Reference","authors":"Xie He, Qiang Zhou, Lei Zhu, Zhihu Wei, Zhang Chen","doi":"10.1109/IWS55252.2022.9977630","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9977630","url":null,"abstract":"To reduce the complex implementation of existing spectrum aliasing-free all-digital radio frequency digital pulse width modulation (RF-PWM) in engineering, a novel RF-PWM all-digital transmitter (ADTx) architecture using sine wave as the reference signal is presented. Four pairs of mutually orthogonal sine wave groups are used as the reference signals of the I and Q quadrature differential PWM units respectively, delta-sigma modulator and digital predistortion are used to suppress modulation noise and spectral aliasing. As a result, alias-free pulse coding can be realized, and the even harmonic components are also suppressed. The feasibility of this novel RF-PWM ADTx is demonstrated, and the system performance is verified by Q PSK and 16QAM signals. Simulation and measurement results show that when compared with the existing RF-PWM ADTx which uses triangular wave as the reference signal, the in-band signal quality and modulation performance of the proposed scheme is similar, but the complexity is much lower.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125530601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9977968
Yi-Feng Ye, Zong-Rui Xu, Linsheng Wu, Jun-Fa Mao
$A$ Ka-band power amplifier with Doherty architecture is designed in 0.15-μm GaAs pHEMT technology. The output combiner is optimized with II-type impedance inverting networks to replace λ/4 inverters for broadband characteristic from 23 to 27.5 GHz under large signal analysis. The design equations are provided. The proposed Doherty power amplifier realizes a gain of 12.5∼15.3 dB in small signal operation and a 25.6∼26.3 dBm saturation output power. The power added efficiency is 34.2∼38.4% at saturation and 18.5∼20.8% at 6-dB power back-off, over the whole 4.5-GHz bandwidth.
{"title":"A Ka-Band GaAs Doherty Power Amplifier with Optimized Output Combiner","authors":"Yi-Feng Ye, Zong-Rui Xu, Linsheng Wu, Jun-Fa Mao","doi":"10.1109/IWS55252.2022.9977968","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9977968","url":null,"abstract":"$A$ Ka-band power amplifier with Doherty architecture is designed in 0.15-μm GaAs pHEMT technology. The output combiner is optimized with II-type impedance inverting networks to replace λ/4 inverters for broadband characteristic from 23 to 27.5 GHz under large signal analysis. The design equations are provided. The proposed Doherty power amplifier realizes a gain of 12.5∼15.3 dB in small signal operation and a 25.6∼26.3 dBm saturation output power. The power added efficiency is 34.2∼38.4% at saturation and 18.5∼20.8% at 6-dB power back-off, over the whole 4.5-GHz bandwidth.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121437484","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 design of 20/30GHz high-gain dual circularly polarized antenna based on the folded reflectarray antenna (FRA) and folded transmitarray antenna (FTA) is presented in this paper for satellite communications systems. Left-hand circularly polarized radiation at 20GHz and right-hand circularly polarized radiation at 30GHz can be achieved by the antenna at the same time. A dualband polarization-sensitive frequency selective surface (FSS) based on antenna-filter-antenna (AFA) technology is used as the subreflector of the antenna. The 1bit phase compensation to form the broadside plane-wave radiation is done by the printed reflectarray with the FRA technique and the subreflector with the FTA technique, respectively. Simulated results show that the antenna gains are relatively stable and the antenna axial ratios are lower than 3dB at the center frequencies of the dual operating band. Moreover, compared with the reconfigurable dualband FRA and dualband FTA, simple DC biasing network should be required in this dualband hybrid antenna design, since the phase compensation at the dualband frequencies is done by the printed reflectarray by the FRA and subreflector by the FTA, respectively. Therefore, the antenna has good dualband electronic beam-steering potential with reconfigurable phase compensation elements.
{"title":"A 20/30GHz Dualband Dual Circularly Polarized Antenna Hybridizing Folded Refelctarray and Folded Transmitarray","authors":"Pan-Pan Zhang, Xi-Cheng Zhu, Xiao-Le Shu, Chen Zhao, Zheng-Zhuang Tao, Peng Chu, Mei Jiang","doi":"10.1109/IWS55252.2022.9977531","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9977531","url":null,"abstract":"A design of 20/30GHz high-gain dual circularly polarized antenna based on the folded reflectarray antenna (FRA) and folded transmitarray antenna (FTA) is presented in this paper for satellite communications systems. Left-hand circularly polarized radiation at 20GHz and right-hand circularly polarized radiation at 30GHz can be achieved by the antenna at the same time. A dualband polarization-sensitive frequency selective surface (FSS) based on antenna-filter-antenna (AFA) technology is used as the subreflector of the antenna. The 1bit phase compensation to form the broadside plane-wave radiation is done by the printed reflectarray with the FRA technique and the subreflector with the FTA technique, respectively. Simulated results show that the antenna gains are relatively stable and the antenna axial ratios are lower than 3dB at the center frequencies of the dual operating band. Moreover, compared with the reconfigurable dualband FRA and dualband FTA, simple DC biasing network should be required in this dualband hybrid antenna design, since the phase compensation at the dualband frequencies is done by the printed reflectarray by the FRA and subreflector by the FTA, respectively. Therefore, the antenna has good dualband electronic beam-steering potential with reconfigurable phase compensation elements.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126309104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9978004
Qiaguang Liu, Wanchen Yang, W. Che, Q. Xue
In this manuscript, a wide-beam wideband magneto-electric (ME) dipole is proposed. The band of the antenna can cover 24.25 to 29.5GHz (19.5%), and after loading the stepped ground, the antenna has a beamwidth of over 110° in the E-plane. Then, the newly designed element is placed with a small distance of 4.5mm (about 0.4AO at 27GHz) for implementing 4x4 wide-angle scanning phased array. Several II-shaped decoupling structures are placed between adjacent elements along the E-plane direction to reduce coupling and therefore improve active S-parameters. The results show that the array can cover the band of 24.25 to 29.5GHz (19.5%), and has a large scanned area from -57° to 56° with a gain drop below 3dB, while all the port isolation is higher than 20dB, and all the active S-parameter is lower than -10dB.
{"title":"Wideband Wide-angle Scanning Millimeter-Wave Phased Array Antenna Based on Magneto-electric Dipole","authors":"Qiaguang Liu, Wanchen Yang, W. Che, Q. Xue","doi":"10.1109/IWS55252.2022.9978004","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9978004","url":null,"abstract":"In this manuscript, a wide-beam wideband magneto-electric (ME) dipole is proposed. The band of the antenna can cover 24.25 to 29.5GHz (19.5%), and after loading the stepped ground, the antenna has a beamwidth of over 110° in the E-plane. Then, the newly designed element is placed with a small distance of 4.5mm (about 0.4AO at 27GHz) for implementing 4x4 wide-angle scanning phased array. Several II-shaped decoupling structures are placed between adjacent elements along the E-plane direction to reduce coupling and therefore improve active S-parameters. The results show that the array can cover the band of 24.25 to 29.5GHz (19.5%), and has a large scanned area from -57° to 56° with a gain drop below 3dB, while all the port isolation is higher than 20dB, and all the active S-parameter is lower than -10dB.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125865052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9977835
Q. Lin, Lining Jia, Haifeng Wu
In order to study the temperature behavior for GaN HEMT E/F3 power amplifier (PA), the series temperature reliability tests are carried out here. The results show that the DC and AC characteristics of this PA have degraded significantly with the rising temperature. Therefore, temperature is an important factor for the GaN HEMT E/F3 PA. In addition, the temperature characteristics of this PA are improved by increasing the substrate doping concentration, selecting the appropriate gate width and designing a reasonable temperature compensation circuit. This research can give an important guidance for the design of the E/F3 power amplifier.
{"title":"Temperature Reliability Exploration of GaN HEMT E/F3 Power Amplifier","authors":"Q. Lin, Lining Jia, Haifeng Wu","doi":"10.1109/IWS55252.2022.9977835","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9977835","url":null,"abstract":"In order to study the temperature behavior for GaN HEMT E/F3 power amplifier (PA), the series temperature reliability tests are carried out here. The results show that the DC and AC characteristics of this PA have degraded significantly with the rising temperature. Therefore, temperature is an important factor for the GaN HEMT E/F3 PA. In addition, the temperature characteristics of this PA are improved by increasing the substrate doping concentration, selecting the appropriate gate width and designing a reasonable temperature compensation circuit. This research can give an important guidance for the design of the E/F3 power amplifier.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125232748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9978051
Zhen Hu, Y. Ge, Z. Chen
Resonant Partially reflective surface (PRS) antennas have limited high-gain performance. This paper investigates and develops non-resonant PRS antennas loaded with a phase-correcting surface (PCS) and fed by a large inter-element spacing feed array. The PCS is used to provide the required compensation phases so that the waves above the PCS are in-phase and the main radiation beam can form. Hence, the high gain bandwidth can be obtained. Our simulation and analysis show that the gain performance improves with the increase of the element spacing of the feed array.
{"title":"Meta Phase-Correcting-Surfaces and Feed Arrays for High-Gain Non-Resonant Partially Reflector Antennas (Invited paper)","authors":"Zhen Hu, Y. Ge, Z. Chen","doi":"10.1109/IWS55252.2022.9978051","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9978051","url":null,"abstract":"Resonant Partially reflective surface (PRS) antennas have limited high-gain performance. This paper investigates and develops non-resonant PRS antennas loaded with a phase-correcting surface (PCS) and fed by a large inter-element spacing feed array. The PCS is used to provide the required compensation phases so that the waves above the PCS are in-phase and the main radiation beam can form. Hence, the high gain bandwidth can be obtained. Our simulation and analysis show that the gain performance improves with the increase of the element spacing of the feed array.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125635963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9977886
Song Zhang, Hao Xue, Xiaonan Wu, Mingyang Chang, Fangjie Cheng, Long Li
The Airy beams have intrigued many researchers because of their unusual characteristics. There are few studies on Airy beams in the microwave field, and the devices currently used to create Airy beams are complex. So, in this paper, a scalar holographic metasurface is proposed to generate a one-dimensional Airy beam, which reduces the complexity of the generation device of the Airy beam. The simulation results at 12 GHz show this paper's proposed method's correctness.
{"title":"Generation of 1D-Airy Beams Based on Scalar Holographic Metasurface","authors":"Song Zhang, Hao Xue, Xiaonan Wu, Mingyang Chang, Fangjie Cheng, Long Li","doi":"10.1109/IWS55252.2022.9977886","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9977886","url":null,"abstract":"The Airy beams have intrigued many researchers because of their unusual characteristics. There are few studies on Airy beams in the microwave field, and the devices currently used to create Airy beams are complex. So, in this paper, a scalar holographic metasurface is proposed to generate a one-dimensional Airy beam, which reduces the complexity of the generation device of the Airy beam. The simulation results at 12 GHz show this paper's proposed method's correctness.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122552947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-12DOI: 10.1109/IWS55252.2022.9978087
Liangjie Qiu, Jie Zhang, Xiuping Li, Wenyu Zhao, Xiaobin Guo
A high-order-mode two-feed orbital angular momentum (OAM) patch antenna at Ka-band is proposed in this paper. The circularly polarized OAM patch antenna has an impedance bandwidth of 23.7% with more than 10-dB return loss. A vortex beam carrying $l=pm 1$ OAM mode is generated with a mode purity over 85% from 26.5 GHz to 33 GHz. Additionally, by loading a low-profile lens, the maximum gain can be improved from 6.7 dBic to 15.7 dBic, and the beam divergence angle converges from 37° to 6°.
{"title":"A High-Order-Mode OAM Patch Antenna with High Gain and Low Divergence","authors":"Liangjie Qiu, Jie Zhang, Xiuping Li, Wenyu Zhao, Xiaobin Guo","doi":"10.1109/IWS55252.2022.9978087","DOIUrl":"https://doi.org/10.1109/IWS55252.2022.9978087","url":null,"abstract":"A high-order-mode two-feed orbital angular momentum (OAM) patch antenna at Ka-band is proposed in this paper. The circularly polarized OAM patch antenna has an impedance bandwidth of 23.7% with more than 10-dB return loss. A vortex beam carrying $l=pm 1$ OAM mode is generated with a mode purity over 85% from 26.5 GHz to 33 GHz. Additionally, by loading a low-profile lens, the maximum gain can be improved from 6.7 dBic to 15.7 dBic, and the beam divergence angle converges from 37° to 6°.","PeriodicalId":126964,"journal":{"name":"2022 IEEE MTT-S International Wireless Symposium (IWS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122720665","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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