Pub Date : 2009-03-02DOI: 10.1109/IWAT.2009.4906887
F. Ferrero, A. Diallo, C. Luxey, B. Derat
In this paper, we demonstrate the possibility to strongly modify the radiated fields of a UMTS handset by using a phased two-element PIFA array. The structure is composed of a 100x40 mm2 metallic ground plane acting as the Printed Circuit Board (PCB) of the mobile phone. Two UMTS PIFAs are located at the top edge of this PCB. They are fed by a double Quasi-Lumped Coupler able to provide a 360° phase difference between its two outputs. By properly choosing the DC bias of the double Quasi-Lumped Coupler, we can set a specific phase difference between the two PIFAs. In this way the two-element array is able to radiate different electromagnetic fields on purpose. Simulated and measured radiation patterns in the two main planes of the chassis are presented for different phase differences. It is especially revealed that the novel two-antenna structure is able to radiate vertically-polarized electric fields in the azimuthal plane of the phone and horizontally-polarized electric fields in the same plane when changing the phase shift between the antennas from 0° to 180°. A large panel of different patterns can also be obtained if the phase difference is chosen between these two values. Potential applications are polarization or pattern-diversity techniques and Specific Absorption Rate reduction for handsets.
{"title":"Phased two-element PIFA for adaptative pattern in UMTS handsets","authors":"F. Ferrero, A. Diallo, C. Luxey, B. Derat","doi":"10.1109/IWAT.2009.4906887","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906887","url":null,"abstract":"In this paper, we demonstrate the possibility to strongly modify the radiated fields of a UMTS handset by using a phased two-element PIFA array. The structure is composed of a 100x40 mm2 metallic ground plane acting as the Printed Circuit Board (PCB) of the mobile phone. Two UMTS PIFAs are located at the top edge of this PCB. They are fed by a double Quasi-Lumped Coupler able to provide a 360° phase difference between its two outputs. By properly choosing the DC bias of the double Quasi-Lumped Coupler, we can set a specific phase difference between the two PIFAs. In this way the two-element array is able to radiate different electromagnetic fields on purpose. Simulated and measured radiation patterns in the two main planes of the chassis are presented for different phase differences. It is especially revealed that the novel two-antenna structure is able to radiate vertically-polarized electric fields in the azimuthal plane of the phone and horizontally-polarized electric fields in the same plane when changing the phase shift between the antennas from 0° to 180°. A large panel of different patterns can also be obtained if the phase difference is chosen between these two values. Potential applications are polarization or pattern-diversity techniques and Specific Absorption Rate reduction for handsets.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130933991","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906966
K. Ito, N. Haga, Masaharu Takahashi, K. Saito
In recent years, body-centric wireless communications become an active area of research due to their various applications such as e-healthcare, support systems for specialized occupations, and personal communications. Since the candidate frequencies for body-centric wireless communications widely range from MHz to GHz, dielectric properties of the human body tissues, relative dimensions of the human body to wavelength, and the propagation channels around the body extremely vary with frequencies. In this paper, to bring objective and unified idea on the frequency characteristics of body-centric wireless communication channels, electric field distributions around the human body wearing a small antenna in a wide frequency range of 2.5 MHz to 2.5 GHz are numerically calculated. The results show that behavior of the electric field distributions around the human body could be broadly divided into two ranges; below 100 MHz and above 250 MHz.
{"title":"Electric field distributions around the human body with a small antenna in the frequency range of 2.5 MHz to 2.5 GHz","authors":"K. Ito, N. Haga, Masaharu Takahashi, K. Saito","doi":"10.1109/IWAT.2009.4906966","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906966","url":null,"abstract":"In recent years, body-centric wireless communications become an active area of research due to their various applications such as e-healthcare, support systems for specialized occupations, and personal communications. Since the candidate frequencies for body-centric wireless communications widely range from MHz to GHz, dielectric properties of the human body tissues, relative dimensions of the human body to wavelength, and the propagation channels around the body extremely vary with frequencies. In this paper, to bring objective and unified idea on the frequency characteristics of body-centric wireless communication channels, electric field distributions around the human body wearing a small antenna in a wide frequency range of 2.5 MHz to 2.5 GHz are numerically calculated. The results show that behavior of the electric field distributions around the human body could be broadly divided into two ranges; below 100 MHz and above 250 MHz.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122490569","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906895
S. Radiom, G. Vandenbosch, G. Gielen
A small size-optimized Printed Tapered Monopole Antenna (PTMA) for UWB application with band-notched characteristic is designed and fabricated for the 3.1 to 10.6 GHz band with notch behavior at 5.8 GHz. Additionally, an efficient technique is applied to this antenna for a further area reduction of 50%. The performance of this miniaturized antenna is compared with the main-size antenna. Using both simulations and measurements the paper analyses and demonstrates in detail the effectiveness of the presented miniaturization technique.
{"title":"Efficient size reduction technique for band-notched planar UWB monopole antennas","authors":"S. Radiom, G. Vandenbosch, G. Gielen","doi":"10.1109/IWAT.2009.4906895","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906895","url":null,"abstract":"A small size-optimized Printed Tapered Monopole Antenna (PTMA) for UWB application with band-notched characteristic is designed and fabricated for the 3.1 to 10.6 GHz band with notch behavior at 5.8 GHz. Additionally, an efficient technique is applied to this antenna for a further area reduction of 50%. The performance of this miniaturized antenna is compared with the main-size antenna. Using both simulations and measurements the paper analyses and demonstrates in detail the effectiveness of the presented miniaturization technique.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114893867","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906952
G. Mumcu, K. Sertel, J. Volakis
Partially coupled microstrip lines are presented to emulate periodic anisotropic crystals exhibiting dispersion curves with degenerate band edges (DBE) or stationary inflection points (SIPs). The subject dispersion curves are designed via equivalent circuit models and used to produce miniature printed antennas. A 6-port circuit is also presented to model three partially coupled lines. Under specific coupling conditions, the latter circuit can realize the SIP associated with the K-ω curves of magnetic photonic crystals (MPCs), without using magnetic materials.
{"title":"Partially coupled microstrip lines for printed antenna miniaturization","authors":"G. Mumcu, K. Sertel, J. Volakis","doi":"10.1109/IWAT.2009.4906952","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906952","url":null,"abstract":"Partially coupled microstrip lines are presented to emulate periodic anisotropic crystals exhibiting dispersion curves with degenerate band edges (DBE) or stationary inflection points (SIPs). The subject dispersion curves are designed via equivalent circuit models and used to produce miniature printed antennas. A 6-port circuit is also presented to model three partially coupled lines. Under specific coupling conditions, the latter circuit can realize the SIP associated with the K-ω curves of magnetic photonic crystals (MPCs), without using magnetic materials.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128127334","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906883
M. Tariqul Islam, M. Shakib, N. Misran, B. Yatim
A folded patch fed compact UWB antenna is proposed and designed. The UWB band is obtained by E-H shaped stacked with H shaped patch, fed with a folded patch feed and the size reduction is realized through the use of shorting wall. The antenna has a compact structure, and the total size is 15 by 14mm by 10mm. A relative impedance bandwidth of 100% (from 3.46 to 10.36 GHz) is achieved. Also, the antenna is able to achieve the stable radiation performance with gain greater than 4 dBi across the UWB band.
{"title":"Design of compact ultrawideband patch antenna for wireless communications","authors":"M. Tariqul Islam, M. Shakib, N. Misran, B. Yatim","doi":"10.1109/IWAT.2009.4906883","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906883","url":null,"abstract":"A folded patch fed compact UWB antenna is proposed and designed. The UWB band is obtained by E-H shaped stacked with H shaped patch, fed with a folded patch feed and the size reduction is realized through the use of shorting wall. The antenna has a compact structure, and the total size is 15 by 14mm by 10mm. A relative impedance bandwidth of 100% (from 3.46 to 10.36 GHz) is achieved. Also, the antenna is able to achieve the stable radiation performance with gain greater than 4 dBi across the UWB band.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"336 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133014239","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906949
Shi Cheng, A. Rydberg, P. Hallbjorner, L. Pettersson, Michael Salter, D. Platt
This paper presents a millimeter-wave tapered slot antenna (TSA) for integration on a 325 μm thick low resistivity silicon substrate, using micromachining techniques. By suspending the radiator on a 5.5 mm x 1.5 mm large benzocyclobutene (BCB) membrane, good antenna performance is achieved at millimeter-wave frequencies. Port impedance and radiation patterns are studied numerically and experimentally. Measurements indicate that this antenna features good impedance matching (S11 ≪ −10 dB) and a gain of ≫ 4.6 dBi from 75 to 110 GHz. The measured results are in good agreement with numerical simulations.
本文提出了一种毫米波锥形缝隙天线(TSA)，该天线采用微加工技术集成在325 μm厚的低电阻硅衬底上。通过将散热器悬挂在5.5 mm x 1.5 mm的大苯并环丁烯(BCB)膜上，可以在毫米波频率下实现良好的天线性能。对端口阻抗和辐射模式进行了数值和实验研究。测量结果表明，该天线具有良好的阻抗匹配(S11≪−10 dB)，在75至110 GHz范围内的增益为4.6 dBi。实测结果与数值模拟结果吻合较好。
{"title":"Millimeter-wave tapered slot antenna for integration on micromachined low resistivity silicon substrates","authors":"Shi Cheng, A. Rydberg, P. Hallbjorner, L. Pettersson, Michael Salter, D. Platt","doi":"10.1109/IWAT.2009.4906949","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906949","url":null,"abstract":"This paper presents a millimeter-wave tapered slot antenna (TSA) for integration on a 325 μm thick low resistivity silicon substrate, using micromachining techniques. By suspending the radiator on a 5.5 mm x 1.5 mm large benzocyclobutene (BCB) membrane, good antenna performance is achieved at millimeter-wave frequencies. Port impedance and radiation patterns are studied numerically and experimentally. Measurements indicate that this antenna features good impedance matching (S11 ≪ −10 dB) and a gain of ≫ 4.6 dBi from 75 to 110 GHz. The measured results are in good agreement with numerical simulations.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133125225","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906981
D. Chang, Chao-Hsiang Liao, P. Hsu
In general, the limited antenna power patterns in frequency domain are used to describe the antenna performance. It is enough to describe the antenna performance in narrow band communication systems. However, the limited antenna power patterns in frequency domain are not enough for ultra wideband (UWB) antennas or arrays in communication systems. The energy pattern of antenna is the total response of power patterns in frequency domain. It will be easier to describe the energy pattern instead of power pattern for UWB antennas. In this paper, electromagnetic energy, electromagnetic power, energy pattern, energy gain, energy directivity and energy efficiency will be discussed. In order to verify the theory of antenna pattern in energy, Yagi Uda antenna, marrow band multibeam smart antenna, UWB bow-tie slot antenna, UWB comb taper slot antenna, and UWB antenna arrays with different element spacing are studied and measured by the impulse time domain system. The energy pattern is quite similar to that of power pattern for narrow band antennas. The grating lobes of UWB antenna array will not occur at the energy pattern even if the element spacing of array is larger than one wavelength.
{"title":"Could the antenna pattern be in energy instead of in power?","authors":"D. Chang, Chao-Hsiang Liao, P. Hsu","doi":"10.1109/IWAT.2009.4906981","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906981","url":null,"abstract":"In general, the limited antenna power patterns in frequency domain are used to describe the antenna performance. It is enough to describe the antenna performance in narrow band communication systems. However, the limited antenna power patterns in frequency domain are not enough for ultra wideband (UWB) antennas or arrays in communication systems. The energy pattern of antenna is the total response of power patterns in frequency domain. It will be easier to describe the energy pattern instead of power pattern for UWB antennas. In this paper, electromagnetic energy, electromagnetic power, energy pattern, energy gain, energy directivity and energy efficiency will be discussed. In order to verify the theory of antenna pattern in energy, Yagi Uda antenna, marrow band multibeam smart antenna, UWB bow-tie slot antenna, UWB comb taper slot antenna, and UWB antenna arrays with different element spacing are studied and measured by the impulse time domain system. The energy pattern is quite similar to that of power pattern for narrow band antennas. The grating lobes of UWB antenna array will not occur at the energy pattern even if the element spacing of array is larger than one wavelength.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133983635","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906899
J. Holopainen, J. Villanen, R. Valkonen, J. Poutanen, O. Kivekas, C. Icheln, P. Vainikainen
A novel antenna structure based on optimized direct feed is presented in this paper. The antenna structure consists of the chassis of a mobile terminal, a feed structure and a matching circuitry. The chassis is cut in two pieces, which are connected with an inductor. The value of the inductor is tuned so that the lowest resonant frequency of the chassis equals the center frequency of the operating band. The feed structure excites very strongly the resonant wavemode of the chassis and thus very large bandwidth is available. The feed structure can be integrated e.g. on the PCB of a mobile terminal and thus the antenna is very low-profile. The antenna structure has been demonstrated with a simulated and measured prototype that covers the GSM850/900 systems.
{"title":"Mobile terminal antennas implemented using optimized direct feed","authors":"J. Holopainen, J. Villanen, R. Valkonen, J. Poutanen, O. Kivekas, C. Icheln, P. Vainikainen","doi":"10.1109/IWAT.2009.4906899","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906899","url":null,"abstract":"A novel antenna structure based on optimized direct feed is presented in this paper. The antenna structure consists of the chassis of a mobile terminal, a feed structure and a matching circuitry. The chassis is cut in two pieces, which are connected with an inductor. The value of the inductor is tuned so that the lowest resonant frequency of the chassis equals the center frequency of the operating band. The feed structure excites very strongly the resonant wavemode of the chassis and thus very large bandwidth is available. The feed structure can be integrated e.g. on the PCB of a mobile terminal and thus the antenna is very low-profile. The antenna structure has been demonstrated with a simulated and measured prototype that covers the GSM850/900 systems.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129036734","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906965
J. Volakis, Gil-Young Lee, D. Psychoudakis, Chi-Chih Chen
We present a modified diversity evaluation method for body-worn antennas. The novelty introduced in this method amounts to considering the human body channel separately from the surrounding environment. This formulation can therefore be easily adapted to different environments via post-processing. Our study for antenna diversity includes three human postures (standing, kneeling, and prone) to increase generality and assess antenna performance. Initially, a variety of single body-worn antenna configurations are investigated to establish the best antenna locations. Subsequently, more antenna locations are included to increase communication reliability using the minimum set of antennas. The considered operational frequency is 500 MHz – 600 MHz and the setup focuses on the upper hemisphere with random polarization excitations.
{"title":"Multiple body-worn antenna diversity","authors":"J. Volakis, Gil-Young Lee, D. Psychoudakis, Chi-Chih Chen","doi":"10.1109/IWAT.2009.4906965","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906965","url":null,"abstract":"We present a modified diversity evaluation method for body-worn antennas. The novelty introduced in this method amounts to considering the human body channel separately from the surrounding environment. This formulation can therefore be easily adapted to different environments via post-processing. Our study for antenna diversity includes three human postures (standing, kneeling, and prone) to increase generality and assess antenna performance. Initially, a variety of single body-worn antenna configurations are investigated to establish the best antenna locations. Subsequently, more antenna locations are included to increase communication reliability using the minimum set of antennas. The considered operational frequency is 500 MHz – 600 MHz and the setup focuses on the upper hemisphere with random polarization excitations.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126831262","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 : 2009-03-02DOI: 10.1109/IWAT.2009.4906916
Chun-Han Chuang, Ju-Hung Chen, Shih-Chia Chiu, H. Wu, Shih-Yuan Chen, P. Hsu
A wideband coplanar waveguide fed asymmetric slot antenna is proposed. By attaching an open-ended and a short-ended slotlines separately to the two slot-ends of a coplanar waveguide, the composite antenna would resonate as a quarter and a half guided wavelength slot monopoles, which correspond to the lower and upper slotline resonances, respectively. Moreover, by embedding an open-ended slotline section in the original open-ended slotline, an additional resonant frequency between the two resonant bands can be excited and the wideband design can be achieved. Measured and simulated characteristics of the antenna are discussed and analyzed.
{"title":"Wideband asymmetric slot antenna fed by coplanar waveguide","authors":"Chun-Han Chuang, Ju-Hung Chen, Shih-Chia Chiu, H. Wu, Shih-Yuan Chen, P. Hsu","doi":"10.1109/IWAT.2009.4906916","DOIUrl":"https://doi.org/10.1109/IWAT.2009.4906916","url":null,"abstract":"A wideband coplanar waveguide fed asymmetric slot antenna is proposed. By attaching an open-ended and a short-ended slotlines separately to the two slot-ends of a coplanar waveguide, the composite antenna would resonate as a quarter and a half guided wavelength slot monopoles, which correspond to the lower and upper slotline resonances, respectively. Moreover, by embedding an open-ended slotline section in the original open-ended slotline, an additional resonant frequency between the two resonant bands can be excited and the wideband design can be achieved. Measured and simulated characteristics of the antenna are discussed and analyzed.","PeriodicalId":166472,"journal":{"name":"2009 IEEE International Workshop on Antenna Technology","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123660642","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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