Pub Date : 2018-06-08DOI: 10.1109/IWAT.2018.8379223
Zhentian Wu, M. Tang, R. Ziolkowski
A design of electrically small, low-profile, dual linearly polarized (LP), Huygens source antenna with high isolation, and broadside radiation patterns with high front forward radiation and low back forward radiation, i.e., high front-to-back ratios (FTBRs), is presented. A prototype dual-LP antenna was fabricated, assembled, and tested. The measured results, in good agreement with their simulated values, confirm that it has an electrically small size (ka=0.904) and low profile (0.0483X0), with port isolation over 25.8 dB within its fractional impedance bandwidth (FBW), 0.46%, where |Sn|< −10 dB. When port 1 (port 2) is excited, the peak realized gain is 2.03 dBi (2.15 dBi) strictly along the broadside direction with the corresponding FTBR being 12.4 dB (12.1 dB).
提出了一种电小、低轮廓、双线极化(LP)、惠更斯源天线的设计，具有高前向辐射和低后向辐射的宽侧辐射模式，即高前后比(FTBRs)。制作、组装和测试了一个原型双lp天线。测量结果与模拟值吻合良好，证实其具有电尺寸小(ka=0.904)和低轮廓(0.0483X0)，在其分数阻抗带宽(FBW)内，端口隔离超过25.8 dB，为0.46%，其中|Sn|<−10 dB。当端口1(端口2)被激励时，严格沿宽方向的峰值实现增益为2.03 dBi (2.15 dBi)，相应的FTBR为12.4 dB (12.1 dB)。
{"title":"Design of dual linearly polarized, electrically small, low-profile, broadside radiating, Huygens source antenna","authors":"Zhentian Wu, M. Tang, R. Ziolkowski","doi":"10.1109/IWAT.2018.8379223","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379223","url":null,"abstract":"A design of electrically small, low-profile, dual linearly polarized (LP), Huygens source antenna with high isolation, and broadside radiation patterns with high front forward radiation and low back forward radiation, i.e., high front-to-back ratios (FTBRs), is presented. A prototype dual-LP antenna was fabricated, assembled, and tested. The measured results, in good agreement with their simulated values, confirm that it has an electrically small size (ka=0.904) and low profile (0.0483X0), with port isolation over 25.8 dB within its fractional impedance bandwidth (FBW), 0.46%, where |Sn|< −10 dB. When port 1 (port 2) is excited, the peak realized gain is 2.03 dBi (2.15 dBi) strictly along the broadside direction with the corresponding FTBR being 12.4 dB (12.1 dB).","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123831462","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 : 2018-06-08DOI: 10.1109/IWAT.2018.8379145
Fengchun Zhang, W. Fan, Xingfeng Wu, G. F. Pedersen
Wireless cable method is a strong candidate to replace conductive cable method for performance testing of multiple-input multiple-output (MIMO) devices. Desired testing signals can be guided over-the-air to the corresponding antenna ports of the mobile terminals, via implementing a compensation filter in the channel emulator (CE). A novel wireless cable method, without the knowledge of transfer matrix between the CE output ports and device antenna ports, was recently proposed in the literature. In this method, the compensation filter was determined based on the average power recorded by each device antenna ports. To speed up the calibration procedure, a one-dimensional monotonic search method was proposed. However, the calibration accuracy was lower comparing with the brute-force method. In this paper, a high-efficiency particle swarm optimization (PSO) algorithm is proposed to determine the compensation filter. Numerical simulation results are provided to validate the effectiveness of PSO algorithm for compensation filter determination in the wireless cable testing.
{"title":"Performance testing of MIMO device with the wireless cable method based on particle swarm optimization algorithm","authors":"Fengchun Zhang, W. Fan, Xingfeng Wu, G. F. Pedersen","doi":"10.1109/IWAT.2018.8379145","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379145","url":null,"abstract":"Wireless cable method is a strong candidate to replace conductive cable method for performance testing of multiple-input multiple-output (MIMO) devices. Desired testing signals can be guided over-the-air to the corresponding antenna ports of the mobile terminals, via implementing a compensation filter in the channel emulator (CE). A novel wireless cable method, without the knowledge of transfer matrix between the CE output ports and device antenna ports, was recently proposed in the literature. In this method, the compensation filter was determined based on the average power recorded by each device antenna ports. To speed up the calibration procedure, a one-dimensional monotonic search method was proposed. However, the calibration accuracy was lower comparing with the brute-force method. In this paper, a high-efficiency particle swarm optimization (PSO) algorithm is proposed to determine the compensation filter. Numerical simulation results are provided to validate the effectiveness of PSO algorithm for compensation filter determination in the wireless cable testing.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129950904","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}
This paper describes a design methodology for five dual-beam filtering patch antennas and their applications to ultra-wideband (UWB) multiple-input multiple-output (MIMO) system. Structures of the five dual-beam filtering patch antennas are the same, but their sizes are different for covering different operation band. With a metal strip and two slots, a wide impedance bandwidth with a stable symmetrical dual-beam radiation pattern is obtained by the patch antenna, and two controllable radiation nulls at the lower and the upper band edge, respectively, are produced, ensuring a sharp roll-off rate at the band edges for both reflection coefficient and realize gain. Five dual-beam filtering patch antennas operating at 3.0–3.8, 3.8–4.8, 4.8–6.15, 6.15–7.98, and 7.98–10.76 GHz, respectively, are applied in a five-element MIMO antenna for covering the whole UWB band (3.1–10.6GHz), and their filtering performances can help to improve the isolation among the different antenna elopements.
{"title":"Dual-beam filtering patch antennas","authors":"Jian‐Feng Li, Zhi-Ning Chen, Duo-long Wu, Yanjie Wu","doi":"10.1109/IWAT.2018.8379214","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379214","url":null,"abstract":"This paper describes a design methodology for five dual-beam filtering patch antennas and their applications to ultra-wideband (UWB) multiple-input multiple-output (MIMO) system. Structures of the five dual-beam filtering patch antennas are the same, but their sizes are different for covering different operation band. With a metal strip and two slots, a wide impedance bandwidth with a stable symmetrical dual-beam radiation pattern is obtained by the patch antenna, and two controllable radiation nulls at the lower and the upper band edge, respectively, are produced, ensuring a sharp roll-off rate at the band edges for both reflection coefficient and realize gain. Five dual-beam filtering patch antennas operating at 3.0–3.8, 3.8–4.8, 4.8–6.15, 6.15–7.98, and 7.98–10.76 GHz, respectively, are applied in a five-element MIMO antenna for covering the whole UWB band (3.1–10.6GHz), and their filtering performances can help to improve the isolation among the different antenna elopements.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"401 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121802863","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 : 2018-03-05DOI: 10.1109/IWAT.2018.8379163
Zehai Wu, B. Wu, Zhenhua Su, Xiuyin Zhang
This paper presents mainly the challenges in the development of base station antennas for the fifth-generation (5G) wireless system. As one of the key technologies, Massive Multiple-Input Multiple-Output (M-MIMO) system can provide huge improvements in terms of system capacity and have been proven both in theory and practical network. The antenna element in the M-MIMO array is discussed at first, and then the multi-system antenna for 5G which is compatible with 4G/3G is involved. As the most important part, three different ways to generate multibeams is presented in details. At the end, the antenna testing method and new material requirement are mentioned.
{"title":"Development challenges for 5G base station antennas","authors":"Zehai Wu, B. Wu, Zhenhua Su, Xiuyin Zhang","doi":"10.1109/IWAT.2018.8379163","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379163","url":null,"abstract":"This paper presents mainly the challenges in the development of base station antennas for the fifth-generation (5G) wireless system. As one of the key technologies, Massive Multiple-Input Multiple-Output (M-MIMO) system can provide huge improvements in terms of system capacity and have been proven both in theory and practical network. The antenna element in the M-MIMO array is discussed at first, and then the multi-system antenna for 5G which is compatible with 4G/3G is involved. As the most important part, three different ways to generate multibeams is presented in details. At the end, the antenna testing method and new material requirement are mentioned.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115064679","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 dual-polarized patch array antenna operating at 28 GHz is designed for 5G communication applications. Based on the conventional PCB process, the antenna is suitable for the phased array module integration, and it can support both horizontal and vertical polarizations. For the single antenna element, it achieves simulated average return loss of less than 10 dB, gain of about 6 dBi from 25 to 30 GHz. In addition, the isolation between the horizontal and vertical polarizations is lower than −20 dB. For the phased array antenna, the simulated peak gain at broadside and 30 degree is 17.6 and 14.6 dBi, respectively. Furthermore, 4 identical 2×2 element subarrays are arranged with special configurations, improving the antenna arrays' cross-polarization suppression and avoiding undesired sidelobes.
{"title":"A low-cost dual-polarized 28 GHz phased array antenna for 5G communications","authors":"Hai-yang Xia, Zhang Tao, Lianming Li, Fu-Chun Zheng","doi":"10.1109/IWAT.2018.8379132","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379132","url":null,"abstract":"A dual-polarized patch array antenna operating at 28 GHz is designed for 5G communication applications. Based on the conventional PCB process, the antenna is suitable for the phased array module integration, and it can support both horizontal and vertical polarizations. For the single antenna element, it achieves simulated average return loss of less than 10 dB, gain of about 6 dBi from 25 to 30 GHz. In addition, the isolation between the horizontal and vertical polarizations is lower than −20 dB. For the phased array antenna, the simulated peak gain at broadside and 30 degree is 17.6 and 14.6 dBi, respectively. Furthermore, 4 identical 2×2 element subarrays are arranged with special configurations, improving the antenna arrays' cross-polarization suppression and avoiding undesired sidelobes.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125978004","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 : 2018-03-05DOI: 10.1109/IWAT.2018.8379219
Agus Hendra Wahyudi, J. Sumantyo, S. Wijaya, A. Munir
This paper presents a polylactid-acid (PLA) based 3D printed circularly polarized 2 × 2 X-band horn array antenna for circularly polarized synthetic aperture radar (CP-SAR) sensor. The use of CP horn array antenna is to overcome some issues related with mismatch orientation and ionospheric effect of linear polarization sensor. The proposed array antenna which is intended to operate at X-band frequency is realized using PLA material through 3D printing technique and fed by series sequential feeding network implemented on a 1.6mm thick NPC-F220A dielectric substrate. From the result, it shows that the proposed CP horn array antenna has 3dB axial ratio bandwidth more than 400MHz in X-band frequency range.
{"title":"PLA-based 3D printed circularly polarized X-band horn array antenna for CP-SAR sensor","authors":"Agus Hendra Wahyudi, J. Sumantyo, S. Wijaya, A. Munir","doi":"10.1109/IWAT.2018.8379219","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379219","url":null,"abstract":"This paper presents a polylactid-acid (PLA) based 3D printed circularly polarized 2 × 2 X-band horn array antenna for circularly polarized synthetic aperture radar (CP-SAR) sensor. The use of CP horn array antenna is to overcome some issues related with mismatch orientation and ionospheric effect of linear polarization sensor. The proposed array antenna which is intended to operate at X-band frequency is realized using PLA material through 3D printing technique and fed by series sequential feeding network implemented on a 1.6mm thick NPC-F220A dielectric substrate. From the result, it shows that the proposed CP horn array antenna has 3dB axial ratio bandwidth more than 400MHz in X-band frequency range.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123983624","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 : 2018-03-05DOI: 10.1109/IWAT.2018.8379240
K. Inoue, T. Nishimura, T. Ohgane, Y. Ogawa
A study on multi-user massive multiple-input multiple-output (MIMO) systems has been done as one of the key technologies for the fifth generation mobile communication system. In massive MIMO systems, more than 100 antenna elements are often used at a base station, and large-dimensional beamforming as multi-user MIMO precoding is needed. Then, heavy computational complexity is a serious issue for multi-user massive MIMO systems. In this paper, we propose a loose beam-forming method only using simple antenna selection focusing on desired signal power. In addition, we evaluate the sum-capacity of the loose beamforming using channel information obtained by a ray-tracing technique. Through the simulation, it has been shown that the performance of the simple antenna selection is better than random selection and show a possibility that the loose beamforming is effective when simple implementation is required.
{"title":"A basic study on antenna selection for loose beamforming in a massive MIMO system","authors":"K. Inoue, T. Nishimura, T. Ohgane, Y. Ogawa","doi":"10.1109/IWAT.2018.8379240","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379240","url":null,"abstract":"A study on multi-user massive multiple-input multiple-output (MIMO) systems has been done as one of the key technologies for the fifth generation mobile communication system. In massive MIMO systems, more than 100 antenna elements are often used at a base station, and large-dimensional beamforming as multi-user MIMO precoding is needed. Then, heavy computational complexity is a serious issue for multi-user massive MIMO systems. In this paper, we propose a loose beam-forming method only using simple antenna selection focusing on desired signal power. In addition, we evaluate the sum-capacity of the loose beamforming using channel information obtained by a ray-tracing technique. Through the simulation, it has been shown that the performance of the simple antenna selection is better than random selection and show a possibility that the loose beamforming is effective when simple implementation is required.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133790998","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 : 2018-03-05DOI: 10.1109/IWAT.2018.8379211
Weijun Zhang, Z. Weng, Lei Wang
A Dual-band MIMO antenna for the 5G communication is proposed in this paper. The proposed antenna consists of four antenna, it operating at 3300–3600 MHz and 4800–5000 MHz. The antenna designed in this letter are different from traditional 5G antennas, the antenna of this paper is perpendicular to the edge of the system circuit board, it can be applied to the popular full-screen mobile phone. According to the simulation results, reflection coefficient of the modulus is less than −6 dB, and the isolation is better than 12 dB over the band-frequency of 3300–3600 MHz and 4800–5000 MHz, it will met the needs of future 5G applications.
{"title":"Design of a dual-band MIMO antenna for 5G smartphone application","authors":"Weijun Zhang, Z. Weng, Lei Wang","doi":"10.1109/IWAT.2018.8379211","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379211","url":null,"abstract":"A Dual-band MIMO antenna for the 5G communication is proposed in this paper. The proposed antenna consists of four antenna, it operating at 3300–3600 MHz and 4800–5000 MHz. The antenna designed in this letter are different from traditional 5G antennas, the antenna of this paper is perpendicular to the edge of the system circuit board, it can be applied to the popular full-screen mobile phone. According to the simulation results, reflection coefficient of the modulus is less than −6 dB, and the isolation is better than 12 dB over the band-frequency of 3300–3600 MHz and 4800–5000 MHz, it will met the needs of future 5G applications.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129270246","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 : 2018-03-05DOI: 10.1109/IWAT.2018.8379170
Yixin Li, H. Zou, Mingkai Wang, Mingzhi Peng, Guangli Yang
An eight-element multiple-input multiple-output (MIMO) antenna applied for 5G and sub-6GHz indoor wireless access points is studied in this paper. The proposed antenna array supports 4 × 4 MIMO in the LTE bands 42/43/46 (3400–3600 MHz, 3600–3800 MHz, and 5150–5925 MHz). Four fork-like electric dipoles disposed at the corners of the system circuit board cover the LTE bands 42/43, while four inverted L-shaped open slots placed along the edges support the LTE band 46. The proposed antenna array exhibits good impedance matching and isolation, with return losses greater than 10 dB and isolations larger than 15 dB. The total efficiency of the antenna array is higher than 70% in the desired operation bands. The envelope correlation coefficient (ECC) and ergodic channel capacity are calculated to verify the MIMO performance.
{"title":"Eight-element MIMO antenna array for 5G/Sub-6GHz indoor micro wireless access points","authors":"Yixin Li, H. Zou, Mingkai Wang, Mingzhi Peng, Guangli Yang","doi":"10.1109/IWAT.2018.8379170","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379170","url":null,"abstract":"An eight-element multiple-input multiple-output (MIMO) antenna applied for 5G and sub-6GHz indoor wireless access points is studied in this paper. The proposed antenna array supports 4 × 4 MIMO in the LTE bands 42/43/46 (3400–3600 MHz, 3600–3800 MHz, and 5150–5925 MHz). Four fork-like electric dipoles disposed at the corners of the system circuit board cover the LTE bands 42/43, while four inverted L-shaped open slots placed along the edges support the LTE band 46. The proposed antenna array exhibits good impedance matching and isolation, with return losses greater than 10 dB and isolations larger than 15 dB. The total efficiency of the antenna array is higher than 70% in the desired operation bands. The envelope correlation coefficient (ECC) and ergodic channel capacity are calculated to verify the MIMO performance.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"226 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116253358","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 : 2018-03-05DOI: 10.1109/IWAT.2018.8379148
Mingming Peng, A. Zhao
In this paper, a high performance 5G millimeter-wave phased antenna array for 37–40 GHz mobile application is proposed. The proposed antenna array is based on dipole antenna with two opening holes. It is shown that compared to previous designs our antenna array design has good antenna performance in terms of antenna gain and scanning property within the entire frequency range.
{"title":"High performance 5G millimeter-wave antenna array for 37–40 GHz mobile application","authors":"Mingming Peng, A. Zhao","doi":"10.1109/IWAT.2018.8379148","DOIUrl":"https://doi.org/10.1109/IWAT.2018.8379148","url":null,"abstract":"In this paper, a high performance 5G millimeter-wave phased antenna array for 37–40 GHz mobile application is proposed. The proposed antenna array is based on dipole antenna with two opening holes. It is shown that compared to previous designs our antenna array design has good antenna performance in terms of antenna gain and scanning property within the entire frequency range.","PeriodicalId":212550,"journal":{"name":"2018 International Workshop on Antenna Technology (iWAT)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130795665","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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