Pub Date : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935223
Haotian Li, Yikai Chen, Shiwen Yang
In this work, an accurate mathematical model for time-modulated antenna arrays (TMAs) is proposed based on the nonideal characteristics in practical TMA developments. Nonideal characteristics including rising edge and falling edge of radio frequency (RF) switches, amplitude and phase imbalances among RF channels, mutual coupling, and polarization purity of antenna elements are investigated and considered in the mathematical model. With the proposed mathematical model, sidelobe levels and cross-polarization levels are accurately predicted for TMAs. Numerical analysis and experimental validations for a Ku-band TMA are presented to demonstrate the effectiveness of the mathematical model. The proposed model provides a reliable approach to predict the performance of TMA with nonideal characteristics in practical developments.
{"title":"Nonideal Mathematical Model Development of Time-Modulated Antenna Arrays","authors":"Haotian Li, Yikai Chen, Shiwen Yang","doi":"10.1109/MAPE53743.2022.9935223","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935223","url":null,"abstract":"In this work, an accurate mathematical model for time-modulated antenna arrays (TMAs) is proposed based on the nonideal characteristics in practical TMA developments. Nonideal characteristics including rising edge and falling edge of radio frequency (RF) switches, amplitude and phase imbalances among RF channels, mutual coupling, and polarization purity of antenna elements are investigated and considered in the mathematical model. With the proposed mathematical model, sidelobe levels and cross-polarization levels are accurately predicted for TMAs. Numerical analysis and experimental validations for a Ku-band TMA are presented to demonstrate the effectiveness of the mathematical model. The proposed model provides a reliable approach to predict the performance of TMA with nonideal characteristics in practical developments.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127918147","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935187
Zhang Tao, Hang Gu, Wei Zhao
In this paper, the line-network-network (LNN) calibration is reformulated based on the T-matrix representation. Firstly, the T-matrices of error boxes are constructed by measuring the line standard, and only three wave ratios need to be solved. On this basis, an unknown obstacle is placed and measured at three positions of the transmission line to solve three wave ratios. Once three wave ratios are obtained, the T-matrices of error boxes are determined. Finally, the validity of the proposed method is proved by the experiment.
{"title":"A Reformulation of LNN Calibration","authors":"Zhang Tao, Hang Gu, Wei Zhao","doi":"10.1109/MAPE53743.2022.9935187","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935187","url":null,"abstract":"In this paper, the line-network-network (LNN) calibration is reformulated based on the T-matrix representation. Firstly, the T-matrices of error boxes are constructed by measuring the line standard, and only three wave ratios need to be solved. On this basis, an unknown obstacle is placed and measured at three positions of the transmission line to solve three wave ratios. Once three wave ratios are obtained, the T-matrices of error boxes are determined. Finally, the validity of the proposed method is proved by the experiment.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132791366","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935185
Wei Zhao, Zhang Tao, Zhao Guo, Hang Gu, Chunyue Cheng
In this paper, a statistical calibration method for the two-port vector network analyzer (VNA) is proposed, where an arbitrary known two-port device and multiple reflections are used as standards. According to our recently proposed theory, the T-matrices of error boxes are constructed by measuring the known two-port standard and only three wave ratios are defined to represent the calibration coefficients. Then, based on the measurements of multiple reflection standards, the three calibration coefficients are initially solved through the ordinary linear regression analysis. After that, with the uncertainties from the connection repeatability introduced to the measurements of multiple reflection standards, the calibration coefficients are secondarily modified by using the weighted linear regression analysis. By this means, the calibration result is obtained under the impact of the connection repeatability, and then used for the error correction of S-parameter measurements. Finally, experiments are performed to verify the proposed method.
{"title":"A Statistical VNA Calibration Method Applying Multiple Reflection Standards","authors":"Wei Zhao, Zhang Tao, Zhao Guo, Hang Gu, Chunyue Cheng","doi":"10.1109/MAPE53743.2022.9935185","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935185","url":null,"abstract":"In this paper, a statistical calibration method for the two-port vector network analyzer (VNA) is proposed, where an arbitrary known two-port device and multiple reflections are used as standards. According to our recently proposed theory, the T-matrices of error boxes are constructed by measuring the known two-port standard and only three wave ratios are defined to represent the calibration coefficients. Then, based on the measurements of multiple reflection standards, the three calibration coefficients are initially solved through the ordinary linear regression analysis. After that, with the uncertainties from the connection repeatability introduced to the measurements of multiple reflection standards, the calibration coefficients are secondarily modified by using the weighted linear regression analysis. By this means, the calibration result is obtained under the impact of the connection repeatability, and then used for the error correction of S-parameter measurements. Finally, experiments are performed to verify the proposed method.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133272378","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935160
Xin-Yu Yang, Hong‐wei Deng, Nan Sun
A high temperature resistant ceramic dielectric rod antenna is presented in this paper. The phase center of dielectric rod antenna is at its top. Ceramic material can also bear high temperature without destroying electrical properties because of thermal stability of ceramic materials. In addition, the heat conduction of ceramics is much smaller than that of metals, which can play a heat insulation effect. Hence, the radiation part of dielectric rod antenna is inserted into the thermal insulation layer so that its top is close to the bottom of the heat shield plate. It can solve the influence on the radiation performance of the antenna due to the "Horn Effect" formed by the gold plating and the bottom metal plate. A broadband ceramic dielectric rod antenna is proposed by electric-thermal co-design. The feed port temperature is less than 100 ℃, which the cable usually can bear the maximum temperature.
{"title":"Electric-Thermal Co-Design of High Temperature Resistance Ceramic Dielectric Rod Antenna","authors":"Xin-Yu Yang, Hong‐wei Deng, Nan Sun","doi":"10.1109/MAPE53743.2022.9935160","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935160","url":null,"abstract":"A high temperature resistant ceramic dielectric rod antenna is presented in this paper. The phase center of dielectric rod antenna is at its top. Ceramic material can also bear high temperature without destroying electrical properties because of thermal stability of ceramic materials. In addition, the heat conduction of ceramics is much smaller than that of metals, which can play a heat insulation effect. Hence, the radiation part of dielectric rod antenna is inserted into the thermal insulation layer so that its top is close to the bottom of the heat shield plate. It can solve the influence on the radiation performance of the antenna due to the \"Horn Effect\" formed by the gold plating and the bottom metal plate. A broadband ceramic dielectric rod antenna is proposed by electric-thermal co-design. The feed port temperature is less than 100 ℃, which the cable usually can bear the maximum temperature.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125662122","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935231
Zebin Yu, Yu-Lu Hu
In this paper, the influences of assembly error on the electromagnetic performance of the antenna array are studied. Taking a 4x4 antenna array as an example, this paper studies the influences of four errors on the antenna performance. And the four cases are: the antenna element spacing along two directions, inserting depth and angle of the KK connector. The conclusions based on results comparison and analysis can be used as precautions for antenna assembly.
{"title":"Research on Influences of Assembly Error on Antenna Array Performance","authors":"Zebin Yu, Yu-Lu Hu","doi":"10.1109/MAPE53743.2022.9935231","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935231","url":null,"abstract":"In this paper, the influences of assembly error on the electromagnetic performance of the antenna array are studied. Taking a 4x4 antenna array as an example, this paper studies the influences of four errors on the antenna performance. And the four cases are: the antenna element spacing along two directions, inserting depth and angle of the KK connector. The conclusions based on results comparison and analysis can be used as precautions for antenna assembly.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123423164","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935235
Rong Liu, Hongchao Wu, Naizhi Wang, Tong Li
In this paper, a wide-angle phased array antenna unit for high-power microwave applications is proposed. The coaxial to waveguide converter is used to realize the connection between the pyramid horn antenna and the SMA. A square coaxial block is used to improve the power capacity of the coaxial probe, and the ridge waveguide in the impedance transformation is wedge-shaped. The adjustment of power capacity is realized by adding a transition cavity structure at the back end of the waveguide, and the VSWR is reduced by introducing a matching groove structure at the bottom of the transition cavity. After the design and optimization of the simulation software, the final active VSWR is less than 1.9 at 7.5GHz-8.8GHz. The overall power capacity of the antenna is 15.88kW, which is 70.81% higher than that of common horn antennas. The scanning characteristics of the unit are simulated by the infinite array method, and the results show that the antenna can achieve ±30° conical scanning and has wide scanning characteristics. The phased array antenna unit has a simple structure, is easy to process, and has certain application value.
{"title":"Design of High Power Microwave Active Phased Array Antenna Unit","authors":"Rong Liu, Hongchao Wu, Naizhi Wang, Tong Li","doi":"10.1109/MAPE53743.2022.9935235","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935235","url":null,"abstract":"In this paper, a wide-angle phased array antenna unit for high-power microwave applications is proposed. The coaxial to waveguide converter is used to realize the connection between the pyramid horn antenna and the SMA. A square coaxial block is used to improve the power capacity of the coaxial probe, and the ridge waveguide in the impedance transformation is wedge-shaped. The adjustment of power capacity is realized by adding a transition cavity structure at the back end of the waveguide, and the VSWR is reduced by introducing a matching groove structure at the bottom of the transition cavity. After the design and optimization of the simulation software, the final active VSWR is less than 1.9 at 7.5GHz-8.8GHz. The overall power capacity of the antenna is 15.88kW, which is 70.81% higher than that of common horn antennas. The scanning characteristics of the unit are simulated by the infinite array method, and the results show that the antenna can achieve ±30° conical scanning and has wide scanning characteristics. The phased array antenna unit has a simple structure, is easy to process, and has certain application value.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131721903","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}
Research on a ground-penetrating radar (GPR) antenna with high-gain and low-coupling. This paper uses the Air-filing method and the gradually-changing structure to optimize the antenna’s performance, separately, by absorbing the energy of the rear wave of the transmitting antenna and increasing the radiation energy of the antenna’s front direction. In this way, an antenna with high gain and still maintain high isolation is obtained. The simulation results and measurements of the proposed antenna have proved the feasibility of this new structure.
{"title":"Research on a Ground-Penetrating Radar Antenna with High-Gain and Low-Coupling","authors":"Yifan Jiang, B. Yuan, Xuchun Shang, Hanqi Mao, Yexiao Gu, Xiaopeng Chen","doi":"10.1109/MAPE53743.2022.9935180","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935180","url":null,"abstract":"Research on a ground-penetrating radar (GPR) antenna with high-gain and low-coupling. This paper uses the Air-filing method and the gradually-changing structure to optimize the antenna’s performance, separately, by absorbing the energy of the rear wave of the transmitting antenna and increasing the radiation energy of the antenna’s front direction. In this way, an antenna with high gain and still maintain high isolation is obtained. The simulation results and measurements of the proposed antenna have proved the feasibility of this new structure.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129505800","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935191
Xin Pang, L. Xia, Jiang Jiao
A microwave gain equalizer has been proposed and analyzed. The equalizer is based on grounded coplanar waveguide (GCPW) with periodic spiral-shaped defected ground structure (DGS), which has a maximum attenuation of 8.5 dB from 6 to 8 GHz. The final size of the equalizer is 9.5mm×3.2mm×0.254mm. The insertion loss of the equalizer is 0.46 dB, and its return loss is better than 11 dB.
{"title":"A Gain Equalizer Based on Grounded Coplanar Waveguide with Sprial-Shaped Defected Ground","authors":"Xin Pang, L. Xia, Jiang Jiao","doi":"10.1109/MAPE53743.2022.9935191","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935191","url":null,"abstract":"A microwave gain equalizer has been proposed and analyzed. The equalizer is based on grounded coplanar waveguide (GCPW) with periodic spiral-shaped defected ground structure (DGS), which has a maximum attenuation of 8.5 dB from 6 to 8 GHz. The final size of the equalizer is 9.5mm×3.2mm×0.254mm. The insertion loss of the equalizer is 0.46 dB, and its return loss is better than 11 dB.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129436673","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935210
Xiaoxuan Huang, X. Zong, Z. Nie, Jun Hu, Liping Zong
With the development of phased array and information processing technologies, active cancellation stealth has become possible. In this paper, a microstrip conformal antenna is designed, which is conformed to the low scattering carrier. When the plane wave source and the antenna port source are excited simultaneously, the total cancellation field is calculated, and the RCS is reduced to a certain extent at some angles after cancellation, which realizes effective stealth of the radar incoming wave direction.
{"title":"Research on Active Cancellation Technology Based on Low Radar Scattering Carrier and Conformal Antenna","authors":"Xiaoxuan Huang, X. Zong, Z. Nie, Jun Hu, Liping Zong","doi":"10.1109/MAPE53743.2022.9935210","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935210","url":null,"abstract":"With the development of phased array and information processing technologies, active cancellation stealth has become possible. In this paper, a microstrip conformal antenna is designed, which is conformed to the low scattering carrier. When the plane wave source and the antenna port source are excited simultaneously, the total cancellation field is calculated, and the RCS is reduced to a certain extent at some angles after cancellation, which realizes effective stealth of the radar incoming wave direction.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"409 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129608966","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 : 2022-08-26DOI: 10.1109/MAPE53743.2022.9935172
Bassel A. Elgharbawy, Mohamed Mobarak, M. Abdalla
This paper presents a 24-44 GHz wideband highly linear and efficient class-AB 2-stacked power amplifier (PA) in 65-nm bulk CMOS process for 5G phased array applications. To boost the output power (POUT) and power added efficiency (PAE) a differential 2-stacked transistors with a higher supply (2V) is used. Cross-Coupled neutralization capacitors and shunt inductors are used at the intermediate nodes to improve the stability and PAE. In the proposed design, multiple techniques are used to achieve high efficient and high linear operation. First, the adaptive bias network (ABN), which is used to adaptively control the bias of the PA stage to increase the gain at high powers (GP), POUT, and enhance the back-off PAE, especially in modulations with high peak to average power ratio (PAPR) (i.e QAM). The second technique is adaptive RC feedback (AFB) which is used to improve the gain flatness (AM-AM) by reducing the feedback as power increases. Lastly, an adaptive capacitive linearizer (ACL) is introduced to improve the (AM-PM) distortion. Transformer-based matching techniques are used to obtain the wideband matching. The proposed PA achieves a saturated POUT of 22.3 dBm, OP1db of 21.75 dBm with GP of 11 dB, and PAEMax of 36%. The measured 6dB power back-off PAE is 26.9% and PAE at 9dB PBO is 19.5% at 24GHz.
{"title":"A 24-44 GHz Highly Linear and Efficient mm-Wave Power Amplifier in 65-nm CMOS for 5G Phased Array Applications","authors":"Bassel A. Elgharbawy, Mohamed Mobarak, M. Abdalla","doi":"10.1109/MAPE53743.2022.9935172","DOIUrl":"https://doi.org/10.1109/MAPE53743.2022.9935172","url":null,"abstract":"This paper presents a 24-44 GHz wideband highly linear and efficient class-AB 2-stacked power amplifier (PA) in 65-nm bulk CMOS process for 5G phased array applications. To boost the output power (POUT) and power added efficiency (PAE) a differential 2-stacked transistors with a higher supply (2V) is used. Cross-Coupled neutralization capacitors and shunt inductors are used at the intermediate nodes to improve the stability and PAE. In the proposed design, multiple techniques are used to achieve high efficient and high linear operation. First, the adaptive bias network (ABN), which is used to adaptively control the bias of the PA stage to increase the gain at high powers (GP), POUT, and enhance the back-off PAE, especially in modulations with high peak to average power ratio (PAPR) (i.e QAM). The second technique is adaptive RC feedback (AFB) which is used to improve the gain flatness (AM-AM) by reducing the feedback as power increases. Lastly, an adaptive capacitive linearizer (ACL) is introduced to improve the (AM-PM) distortion. Transformer-based matching techniques are used to obtain the wideband matching. The proposed PA achieves a saturated POUT of 22.3 dBm, OP1db of 21.75 dBm with GP of 11 dB, and PAEMax of 36%. The measured 6dB power back-off PAE is 26.9% and PAE at 9dB PBO is 19.5% at 24GHz.","PeriodicalId":442568,"journal":{"name":"2022 IEEE 9th International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115134214","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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