Pub Date : 2010-10-28DOI: 10.1109/ARRAY.2010.5613249
Danial Ehyaie, A. Mortazawi
This paper presents a new design for a low cost, low complexity phased array. The proposed design allows control of the phase progression in the entire phased array by using only two phase shifters. As a result, cost and complexity of the phased arrays based on this approach can be significantly reduced. The proposed phased array is composed of directional couplers, amplifying stages, power combiners and two phase shifters. The phase shifters are simple and compact consisting of varactor diodes and inductors. As proof-of-principle, a 2 GHz eight-element phased array with an approximate scan angle of 25 degrees is presented.
{"title":"A new approach to design low cost, low complexity phased arrays","authors":"Danial Ehyaie, A. Mortazawi","doi":"10.1109/ARRAY.2010.5613249","DOIUrl":"https://doi.org/10.1109/ARRAY.2010.5613249","url":null,"abstract":"This paper presents a new design for a low cost, low complexity phased array. The proposed design allows control of the phase progression in the entire phased array by using only two phase shifters. As a result, cost and complexity of the phased arrays based on this approach can be significantly reduced. The proposed phased array is composed of directional couplers, amplifying stages, power combiners and two phase shifters. The phase shifters are simple and compact consisting of varactor diodes and inductors. As proof-of-principle, a 2 GHz eight-element phased array with an approximate scan angle of 25 degrees is presented.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121613390","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5517621
Ali Hassan Khalill, D. Passerieux
In this paper, and for the first time to the best of our knowledge, a very challenging 4-pole quasi-elliptic filter in the submillimetric wave range is studied and fabricated by the LTCC technology. The proposed 4-pole filter, centered at 150 GHz with 2 GHz band pass, is described and the coupling apertures used to provide the required positive and negative couplings are studied. The measured response is in very good agreement with the predicted behavior with a central frequency of 149.7 GHz (0.2% variation) and a 2.02 GHz band pass. The obtained manufactured filter is compact in size (3.32 mm x 2.36 mm x 0.6 mm), has a high performance with 5.5 dB insertion loss at the central frequency and a transmission attenuation over 20 dB for fo ± 1.6 GHz. Index Terms Low temperature co-fired ceramic (LTCC), quasi-elliptic filter, resonant cavity, submillimeter wave range.
本文首次在我们所知的范围内，利用LTCC技术研究并制作了一个极具挑战性的亚毫米波范围内的四极准椭圆滤波器。本文描述了以150ghz为中心、2ghz带通的四极滤波器，并研究了用于提供所需正、负耦合的耦合孔径。在中心频率为149.7 GHz(误差0.2%)，带通为2.02 GHz的情况下，实测响应与预测行为非常吻合。所制备的滤波器尺寸紧凑(3.32 mm x 2.36 mm x 0.6 mm)，在中心频率处具有5.5 dB的插入损耗，在±1.6 GHz时传输衰减超过20 dB。低温共烧陶瓷(LTCC)，准椭圆滤波器，谐振腔，亚毫米波范围。
{"title":"Quasi-elliptic 150 GHz highly selective LTCC filter","authors":"Ali Hassan Khalill, D. Passerieux","doi":"10.1109/MWSYM.2010.5517621","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5517621","url":null,"abstract":"In this paper, and for the first time to the best of our knowledge, a very challenging 4-pole quasi-elliptic filter in the submillimetric wave range is studied and fabricated by the LTCC technology. The proposed 4-pole filter, centered at 150 GHz with 2 GHz band pass, is described and the coupling apertures used to provide the required positive and negative couplings are studied. The measured response is in very good agreement with the predicted behavior with a central frequency of 149.7 GHz (0.2% variation) and a 2.02 GHz band pass. The obtained manufactured filter is compact in size (3.32 mm x 2.36 mm x 0.6 mm), has a high performance with 5.5 dB insertion loss at the central frequency and a transmission attenuation over 20 dB for fo ± 1.6 GHz. Index Terms Low temperature co-fired ceramic (LTCC), quasi-elliptic filter, resonant cavity, submillimeter wave range.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123127067","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5515745
M. Kishihara, M. Kato, H. Ikeuchi, K. Murai, Y. Ukita, Y. Utsumi, T. Kawai, I. Ohta
A metallic waveguide is one of effective media for millimeter- and submillimeter-waves because of the advantage of low-loss. This paper describes trial fabrication of a PTFE-filled waveguide bandpass filter (BPF) with the use of the SR (synchrotron radiation) direct etching process of PTFE, sputter deposition of metal, and electroplating. PTFE is known as a difficult material to process at high precision. However, it has been reported that PTFE microstructures can be fabricated by the direct exposure to SR. In this paper, an iris-coupled waveguide BPF with 5-stage Chebyshev response is designed at Q-band, and the fabrication procedure for the PTFE-filled waveguide BPF is described. The measurement results of the fabricated BPF are shown.
{"title":"Fabrication of PTFE-filled waveguide bandpass filter using SR direct etching","authors":"M. Kishihara, M. Kato, H. Ikeuchi, K. Murai, Y. Ukita, Y. Utsumi, T. Kawai, I. Ohta","doi":"10.1109/MWSYM.2010.5515745","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5515745","url":null,"abstract":"A metallic waveguide is one of effective media for millimeter- and submillimeter-waves because of the advantage of low-loss. This paper describes trial fabrication of a PTFE-filled waveguide bandpass filter (BPF) with the use of the SR (synchrotron radiation) direct etching process of PTFE, sputter deposition of metal, and electroplating. PTFE is known as a difficult material to process at high precision. However, it has been reported that PTFE microstructures can be fabricated by the direct exposure to SR. In this paper, an iris-coupled waveguide BPF with 5-stage Chebyshev response is designed at Q-band, and the fabrication procedure for the PTFE-filled waveguide BPF is described. The measurement results of the fabricated BPF are shown.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124364622","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5517765
Kaixue Ma, K. Yeo
low pass filters with ultra-wide band rejection and compact size by using radial stub and proposed radial stub with transformer are investigated. The stopband skirt selectivity and stopband width of lowpass filter are improved through generation of multiple zero points using proposed new structures. The implemented low pass filters with cutoff frequency fc of 3GHz demonstrates stopband rejection more than 35dB up to 8fc and insertion loss better than 1dB. The size of the low pass filters are only 0.4λg × 0.155λg and 0.31λg × 0.24λg, (λg is the guide wavelength at center cutoff frequency) .
{"title":"Novel low cost compact size planar low pass filters with deep skirt selectivity and wide stopband rejection","authors":"Kaixue Ma, K. Yeo","doi":"10.1109/MWSYM.2010.5517765","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5517765","url":null,"abstract":"low pass filters with ultra-wide band rejection and compact size by using radial stub and proposed radial stub with transformer are investigated. The stopband skirt selectivity and stopband width of lowpass filter are improved through generation of multiple zero points using proposed new structures. The implemented low pass filters with cutoff frequency f<inf>c</inf> of 3GHz demonstrates stopband rejection more than 35dB up to 8f<inf>c</inf> and insertion loss better than 1dB. The size of the low pass filters are only 0.4λg × 0.155λg and 0.31λg × 0.24λg, (λg is the guide wavelength at center cutoff frequency) .","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116967234","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5517633
P. Sumant, Hong Wu, A. Cangellaris, N. Aluru
A methodology is proposed for the model order reduction of finite element approximations of passive electromagnetic devices under random input conditions. In this approach, the reduced order system matrices are represented in terms of their convergent orthogonal polynomial expansions of input random variables. The coefficients of these polynomials, which are matrices, are obtained by repeated, deterministic model order reduction of finite element models generated for specific values of the input random variables. These values are chosen efficiently in a multi-dimensional grid using a Smolyak algorithm. The stochastic reduced order model is represented in the form of an augmented system which can be used for generating the desired statistics of the specific system response. The proposed method provides for significant improvement in computational efficiency over standard Monte Carlo.
{"title":"A sparse grid based collocation method for model order reduction of finite element approximations of passive electromagnetic devices under uncertainty","authors":"P. Sumant, Hong Wu, A. Cangellaris, N. Aluru","doi":"10.1109/MWSYM.2010.5517633","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5517633","url":null,"abstract":"A methodology is proposed for the model order reduction of finite element approximations of passive electromagnetic devices under random input conditions. In this approach, the reduced order system matrices are represented in terms of their convergent orthogonal polynomial expansions of input random variables. The coefficients of these polynomials, which are matrices, are obtained by repeated, deterministic model order reduction of finite element models generated for specific values of the input random variables. These values are chosen efficiently in a multi-dimensional grid using a Smolyak algorithm. The stochastic reduced order model is represented in the form of an augmented system which can be used for generating the desired statistics of the specific system response. The proposed method provides for significant improvement in computational efficiency over standard Monte Carlo.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117354593","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5517804
R. Tinivella, S. Shen, M. Pirola, G. Ghione, V. Camarchia
A device-level SPICE library based on an integrated organic pentacene OFET process by Philips has been developed to carry out the design of the analog and digital subsystems required in the implementation of low-cost high volume RFIDs. The OFET model was fitted through the use of a modified MOSFET SPICE model. Simulations are shown to validate the technological choice and to demonstrate the feasibility in the implementation of a passive RFID operating at 12 V bias voltage.
{"title":"A device-level analog and digital subsystem SPICE library for the design of low-cost pentacene OFET RFIDs","authors":"R. Tinivella, S. Shen, M. Pirola, G. Ghione, V. Camarchia","doi":"10.1109/MWSYM.2010.5517804","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5517804","url":null,"abstract":"A device-level SPICE library based on an integrated organic pentacene OFET process by Philips has been developed to carry out the design of the analog and digital subsystems required in the implementation of low-cost high volume RFIDs. The OFET model was fitted through the use of a modified MOSFET SPICE model. Simulations are shown to validate the technological choice and to demonstrate the feasibility in the implementation of a passive RFID operating at 12 V bias voltage.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121214805","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5515428
Yizhuo Yang, C. Lim, A. Nirmalathas
We propose an efficient transmission scheme for Hybrid Fiber-Radio (HFR) system using a digitized RF-over-fiber (DRoF) technique, which can simplify frequency translation functions and supports multiple wireless services. We experimentally demonstrate a DRoF-HFR downlink for the transmission of GSM, UMTS and WiMAX services, with a minimum sampling rate of 50 MHz and an overall optical data rate of 400 Mb/s. Experimental results show that the amount of amplification required for the image at the desired wireless carrier frequency becomes significant when the image resides in the 20th or higher order Nyquist zone.
{"title":"Experimental demonstration of a downlink multi-channel Hybrid Fiber-Radio using digitized RF-over-fiber technique","authors":"Yizhuo Yang, C. Lim, A. Nirmalathas","doi":"10.1109/MWSYM.2010.5515428","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5515428","url":null,"abstract":"We propose an efficient transmission scheme for Hybrid Fiber-Radio (HFR) system using a digitized RF-over-fiber (DRoF) technique, which can simplify frequency translation functions and supports multiple wireless services. We experimentally demonstrate a DRoF-HFR downlink for the transmission of GSM, UMTS and WiMAX services, with a minimum sampling rate of 50 MHz and an overall optical data rate of 400 Mb/s. Experimental results show that the amount of amplification required for the image at the desired wireless carrier frequency becomes significant when the image resides in the 20th or higher order Nyquist zone.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121239911","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5515076
Yuandan Dong, T. Itoh
Based on the composite right/left-handed (CRLH) half-mode substrate integrated waveguide (HMSIW) transmission line (TL), a dual-band rat-race coupler is implemented and presented in this paper. The CRLH behavior of the HMSIW TL is obtained by etching the interdigital slot on the waveguide surface. It supports the propagation of the backward-wave below the characteristic waveguide cutoff frequency in the left-handed (LH) region and the forward-wave in the right-handed (RH) region. This attribute (phase advance and phase delay at different frequencies) is applied to the design of a dual-band rat-race coupler. Equivalent circuit and dispersion diagram are discussed. Theory and synthesis procedures are provided. Couplers based on the conventional HMSIW and CRLH HMSIW are designed, fabricated and compared. Their 180°-out-of-phase and in-phase operations are verified. Good agreement between the simulation and measurement is observed.
{"title":"Application of composite right/left-handed half-mode substrate integrated waveguide to the design of a dual-band rat-race coupler","authors":"Yuandan Dong, T. Itoh","doi":"10.1109/MWSYM.2010.5515076","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5515076","url":null,"abstract":"Based on the composite right/left-handed (CRLH) half-mode substrate integrated waveguide (HMSIW) transmission line (TL), a dual-band rat-race coupler is implemented and presented in this paper. The CRLH behavior of the HMSIW TL is obtained by etching the interdigital slot on the waveguide surface. It supports the propagation of the backward-wave below the characteristic waveguide cutoff frequency in the left-handed (LH) region and the forward-wave in the right-handed (RH) region. This attribute (phase advance and phase delay at different frequencies) is applied to the design of a dual-band rat-race coupler. Equivalent circuit and dispersion diagram are discussed. Theory and synthesis procedures are provided. Couplers based on the conventional HMSIW and CRLH HMSIW are designed, fabricated and compared. Their 180°-out-of-phase and in-phase operations are verified. Good agreement between the simulation and measurement is observed.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121317851","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5517342
M. Tsai, F. Hsueh, C. Jou, Ming-Hsiang Song, J. Tseng, S. Hsu, Sean Chen
A new ESD topology is proposed for RF low-noise amplifier (LNA). By using the modified silicon-controlled rectifier (MSCR) in conjunction with a P+/N-well diode clamp, a 5.8-GHz LNA with 6.5-kV ESD protection circuit is demonstrated by a 65-nm CMOS technology. Compared with the reference design, the new topology enhances the ESD level from 3.5 kV to 6.5 kV for human body model (HBM) while the noise figure (NF) is only 0.13 dB higher. Under a supply voltage of 1.2 V and drain current of 6.5 mA, the proposed ESD-protected LNA has a NF of 2.57 dB with an associated power gain of 16.7 dB. The input third-order intercept point (IIP3) is −11 dBm and the input and output return losses are below −15.9 dB and −20 dB, respectively.
{"title":"A 6.5kV ESD-protected low noise amplifier in 65-nm CMOS","authors":"M. Tsai, F. Hsueh, C. Jou, Ming-Hsiang Song, J. Tseng, S. Hsu, Sean Chen","doi":"10.1109/MWSYM.2010.5517342","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5517342","url":null,"abstract":"A new ESD topology is proposed for RF low-noise amplifier (LNA). By using the modified silicon-controlled rectifier (MSCR) in conjunction with a P+/N-well diode clamp, a 5.8-GHz LNA with 6.5-kV ESD protection circuit is demonstrated by a 65-nm CMOS technology. Compared with the reference design, the new topology enhances the ESD level from 3.5 kV to 6.5 kV for human body model (HBM) while the noise figure (NF) is only 0.13 dB higher. Under a supply voltage of 1.2 V and drain current of 6.5 mA, the proposed ESD-protected LNA has a NF of 2.57 dB with an associated power gain of 16.7 dB. The input third-order intercept point (IIP3) is −11 dBm and the input and output return losses are below −15.9 dB and −20 dB, respectively.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125842415","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 : 2010-05-23DOI: 10.1109/MWSYM.2010.5516038
V. Vadalà, A. Raffo, S. Di Falco, G. Vannini
Load-pull measurement systems are the most common and powerful instruments used for the design of power amplifiers. In fact, they allow to directly obtain output power, efficiency and gain contours which give a clear idea of the electron device optimum termination for the selected operation. Nevertheless, such measurement systems are also very expensive, especially if high frequencies and high power levels are addressed. In this paper, a new technique for drawing load-pull contours is presented which jointly exploits both large-signal low-frequency I/V device measurements and a nonlinear capacitance-based model, the latter one being obtained on the basis of bias-and frequency-dependent small-signal S-parameters. The proposed approach achieves the same level of accuracy of high-frequency measurement systems, by using general purpose instrumentation available in microwave laboratories. Different experimental examples, based on power GaN FETs, are provided to demonstrate the validity of the described technique.
{"title":"A low-cost and accurate technique for the prediction of load-pull contours","authors":"V. Vadalà, A. Raffo, S. Di Falco, G. Vannini","doi":"10.1109/MWSYM.2010.5516038","DOIUrl":"https://doi.org/10.1109/MWSYM.2010.5516038","url":null,"abstract":"Load-pull measurement systems are the most common and powerful instruments used for the design of power amplifiers. In fact, they allow to directly obtain output power, efficiency and gain contours which give a clear idea of the electron device optimum termination for the selected operation. Nevertheless, such measurement systems are also very expensive, especially if high frequencies and high power levels are addressed. In this paper, a new technique for drawing load-pull contours is presented which jointly exploits both large-signal low-frequency I/V device measurements and a nonlinear capacitance-based model, the latter one being obtained on the basis of bias-and frequency-dependent small-signal S-parameters. The proposed approach achieves the same level of accuracy of high-frequency measurement systems, by using general purpose instrumentation available in microwave laboratories. Different experimental examples, based on power GaN FETs, are provided to demonstrate the validity of the described technique.","PeriodicalId":341557,"journal":{"name":"2010 IEEE MTT-S International Microwave Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123295194","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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