|In this paper, wideband and high efficiency millimeter-wave circular Airy orbital angular momentum (OAM) beams, which have desired multiplexing OAM modes, directions, and beam numbers, are generated by the proposed three metal layer transmission metasurfaces (TMSs) with size 12 (cid:21) 0 (cid:2) 12 (cid:21) 0 based on the Airy-OAM phase superposition method. The measured results indicate non-diffracting propagation distance 31 (cid:21) 0 , autofocusing property, high aperture efficiency 13.1%, and wideband 16.8% (28 GHz{33 GHz). The design method can be used for circular Airy OAM beam generation in point-to-point, point-to-multipoint wireless power transmission (WPT), and OAM mode multiplexing communication systems.
{"title":"MILLIMETER-WAVE WIDEBAND HIGH EFFECIENCY CIRCULAR AIRY OAM MULTIBEAMS WITH MULTIPLEXING OAM MODES BASED ON TRANSMISSION METASURFACES","authors":"Hui-fen Huang, Hong-Ming Huang","doi":"10.2528/pier22022405","DOIUrl":"https://doi.org/10.2528/pier22022405","url":null,"abstract":"|In this paper, wideband and high efficiency millimeter-wave circular Airy orbital angular momentum (OAM) beams, which have desired multiplexing OAM modes, directions, and beam numbers, are generated by the proposed three metal layer transmission metasurfaces (TMSs) with size 12 (cid:21) 0 (cid:2) 12 (cid:21) 0 based on the Airy-OAM phase superposition method. The measured results indicate non-diffracting propagation distance 31 (cid:21) 0 , autofocusing property, high aperture efficiency 13.1%, and wideband 16.8% (28 GHz{33 GHz). The design method can be used for circular Airy OAM beam generation in point-to-point, point-to-multipoint wireless power transmission (WPT), and OAM mode multiplexing communication systems.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"352 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76415001","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}
|Since the (cid:12)rst working multilevel fast multipole algorithm (MLFMA) for electromagnetic simulations was proposed by Chew’s group in 1995, this algorithm has been recognized as one of the most powerful tools for numerical solutions of extremely large electromagnetic problems with complex geometries. It has been parallelized with different strategies to explore the computing power of supercomputers, increasing the size of solvable problems from millions to tens of billions of unknowns, thereby addressing the crucial demand arising from practical applications in a sense. This paper provides a comprehensive review of state-of-the-art parallel approaches of the MLFMA, especially on a newly proposed ternary parallelization scheme and its acceleration on graphics processing unit (GPU) clusters. We discuss and numerically study the advantages of the ternary parallelization scheme and demonstrate its (cid:13)exibility and efficiency.
{"title":"MASSIVELY PARALLEL MULTILEVEL FAST MULTIPOLE ALGORITHM FOR EXTREMELY LARGE-SCALE ELECTROMAGNETIC SIMULATIONS: A REVIEW","authors":"Wei-Jia He, Xiao-Wei Huang, Ming-lin Yang, X. Sheng","doi":"10.2528/pier22011202","DOIUrl":"https://doi.org/10.2528/pier22011202","url":null,"abstract":"|Since the (cid:12)rst working multilevel fast multipole algorithm (MLFMA) for electromagnetic simulations was proposed by Chew’s group in 1995, this algorithm has been recognized as one of the most powerful tools for numerical solutions of extremely large electromagnetic problems with complex geometries. It has been parallelized with different strategies to explore the computing power of supercomputers, increasing the size of solvable problems from millions to tens of billions of unknowns, thereby addressing the crucial demand arising from practical applications in a sense. This paper provides a comprehensive review of state-of-the-art parallel approaches of the MLFMA, especially on a newly proposed ternary parallelization scheme and its acceleration on graphics processing unit (GPU) clusters. We discuss and numerically study the advantages of the ternary parallelization scheme and demonstrate its (cid:13)exibility and efficiency.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"242 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82759027","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}
|We introduce the concept of gap Zak or Chern topological invariants for photonic crystals of various dimensionalities. Speci(cid:12)cally, we consider a case where Tamm states are formed at an interface of two semi-in(cid:12)nite Bragg mirrors and derive the formulism for gap Zak phases of two constituent Bragg mirrors. We demonstrate that gap topological numbers are instrumental in studies of interface states both in conventional and photonic crystals.
{"title":"TAMM STATES AND GAP TOPOLOGICAL NUMBERS IN PHOTONIC CRYSTALS (INVITED PAPER)","authors":"Junhui Cao, A. Kavokin, A. Nalitov","doi":"10.2528/pier22011601","DOIUrl":"https://doi.org/10.2528/pier22011601","url":null,"abstract":"|We introduce the concept of gap Zak or Chern topological invariants for photonic crystals of various dimensionalities. Speci(cid:12)cally, we consider a case where Tamm states are formed at an interface of two semi-in(cid:12)nite Bragg mirrors and derive the formulism for gap Zak phases of two constituent Bragg mirrors. We demonstrate that gap topological numbers are instrumental in studies of interface states both in conventional and photonic crystals.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77675792","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}
Jing Luo, Zijian Lin, Yuxin Xing, E. Forsberg, Chengdong Wu, Xinhua Zhu, Tingbiao Guo, Gaoxuan Wang, Beilei Bian, Dun Wu, Sailing He
A portable 4D snapshot hyperspectral imager (P4DS imager) with compact size, fast imaging time, low cost, and simple design is proposed and demonstrated. The key components of the system are a projector, a liquid crystal tunable filter (LCTF), and a camera. It has two operating modes depending on the set state of the LCTF: a 3D light measurement mode that produces a 3D point cloud reconstruction of an object and a hyperspectral imaging mode yielding spectral data. The camera imaging plane is the same for both operating modes allowing the collected spatial and spectral data to be directly fused into a 4D data set without post-processing. The P4DS imager has excellent performance with a spectral resolution of 10 nm, a spatial depth accuracy of 55.7μm, and a total 4D imaging time of 0.8 s. 4D imaging experiments of three different samples, namely, a colored figurine, green broccoli, and a human face, are presented to demonstrate the efficiency and applicability of the system. Due to being cost-effective, portable, and good imaging performance, the proposed system is suitable for commercialization and mass production.
{"title":"PORTABLE 4D SNAPSHOT HYPERSPECTRAL IMAGER FOR FASTSPECTRAL AND SURFACE MORPHOLOGY MEASUREMENTS","authors":"Jing Luo, Zijian Lin, Yuxin Xing, E. Forsberg, Chengdong Wu, Xinhua Zhu, Tingbiao Guo, Gaoxuan Wang, Beilei Bian, Dun Wu, Sailing He","doi":"10.2528/pier22021702","DOIUrl":"https://doi.org/10.2528/pier22021702","url":null,"abstract":"A portable 4D snapshot hyperspectral imager (P4DS imager) with compact size, fast imaging time, low cost, and simple design is proposed and demonstrated. The key components of the system are a projector, a liquid crystal tunable filter (LCTF), and a camera. It has two operating modes depending on the set state of the LCTF: a 3D light measurement mode that produces a 3D point cloud reconstruction of an object and a hyperspectral imaging mode yielding spectral data. The camera imaging plane is the same for both operating modes allowing the collected spatial and spectral data to be directly fused into a 4D data set without post-processing. The P4DS imager has excellent performance with a spectral resolution of 10 nm, a spatial depth accuracy of 55.7μm, and a total 4D imaging time of 0.8 s. 4D imaging experiments of three different samples, namely, a colored figurine, green broccoli, and a human face, are presented to demonstrate the efficiency and applicability of the system. Due to being cost-effective, portable, and good imaging performance, the proposed system is suitable for commercialization and mass production.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83457457","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}
Reflection reduction metasurface is capable of suppressing the radar cross section of a target, which is of great importance in stealth technology. However, it is still a challenge to realize broadband and low-profile simultaneously within a simple design. Here, we experimentally demonstrate an ultra-thin wideband reflection reduction metasurface, which is achieved by utilizing polarization conversion instead of resonant absorption. The simple cut-wire unit cell is adopted to perform efficient cross polarization conversion, which leads to a polarization conversion ratio above 90% ranging from 8.4 to 14.7GHz. By arranging the 0/1 units in chessboard layout, the reflection reduction reaches 10 dB from 8.1GHz to 14.6GHz. Measured results agree well with simulated ones, which validates the effectiveness of the proposed structure. The ratio of thickness to maximum wavelength reaches 0.56 while the relative bandwidth reaches 57.3%, demonstrating an excellent comprehensive performance. Since our structure consists of refractory ceramic materials, it is promising for radar cross section reduction in high temperature environment.
{"title":"AN ULTRA-THIN WIDEBAND REFLECTION REDUCTION METASURFACE BASED ON POLARIZATION CONVERSION","authors":"Tiancheng Han, Kaihuai Wen, Zixuan Xie, Xiuli Yue","doi":"10.2528/pier21121405","DOIUrl":"https://doi.org/10.2528/pier21121405","url":null,"abstract":"Reflection reduction metasurface is capable of suppressing the radar cross section of a target, which is of great importance in stealth technology. However, it is still a challenge to realize broadband and low-profile simultaneously within a simple design. Here, we experimentally demonstrate an ultra-thin wideband reflection reduction metasurface, which is achieved by utilizing polarization conversion instead of resonant absorption. The simple cut-wire unit cell is adopted to perform efficient cross polarization conversion, which leads to a polarization conversion ratio above 90% ranging from 8.4 to 14.7GHz. By arranging the 0/1 units in chessboard layout, the reflection reduction reaches 10 dB from 8.1GHz to 14.6GHz. Measured results agree well with simulated ones, which validates the effectiveness of the proposed structure. The ratio of thickness to maximum wavelength reaches 0.56 while the relative bandwidth reaches 57.3%, demonstrating an excellent comprehensive performance. Since our structure consists of refractory ceramic materials, it is promising for radar cross section reduction in high temperature environment.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85344261","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}
Xin Li, Hanqing Yang, R. Shao, Feng Zhai, Guobiao Liu, Z. Wang, Hongyang Gao, Ge Fan, J. Wu, Q. Cheng, T. Cui
{"title":"LOW COST AND HIGH PERFORMANCE 5-BIT PROGRAMMABLE PHASED ARRAY ANTENNA AT KU-BAND","authors":"Xin Li, Hanqing Yang, R. Shao, Feng Zhai, Guobiao Liu, Z. Wang, Hongyang Gao, Ge Fan, J. Wu, Q. Cheng, T. Cui","doi":"10.2528/pier22052806","DOIUrl":"https://doi.org/10.2528/pier22052806","url":null,"abstract":"","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78955537","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}
|Exact solutions to Maxwell equations with topological charge based on a modi(cid:12)cation to Brittingham’s single cycle pulses are analyzed demonstrating that they have (cid:12)nite values of energy, momentum, and angular momentum. Moreover, the ratio of angular momentum to energy is bounded due to the dependence of the mean frequency on topological charge. We have also analyzed the skyrmionic texture of the electric and magnetic (cid:12)elds showing that it is possible to obtain skyrmionic numbers higher than the one for the magnetic (cid:12)eld by means of a superposition of pulses with different topological charges and null skyrmionic number.
{"title":"Few-cycle Electromagnetic Pulses with Finite Energy and Bounded Angular Momentum: Analysis of the Skyrmionic Texture at Focal Plane","authors":"L. Carretero, P. Acebal, S. Blaya","doi":"10.2528/pier22071603","DOIUrl":"https://doi.org/10.2528/pier22071603","url":null,"abstract":"|Exact solutions to Maxwell equations with topological charge based on a modi(cid:12)cation to Brittingham’s single cycle pulses are analyzed demonstrating that they have (cid:12)nite values of energy, momentum, and angular momentum. Moreover, the ratio of angular momentum to energy is bounded due to the dependence of the mean frequency on topological charge. We have also analyzed the skyrmionic texture of the electric and magnetic (cid:12)elds showing that it is possible to obtain skyrmionic numbers higher than the one for the magnetic (cid:12)eld by means of a superposition of pulses with different topological charges and null skyrmionic number.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81157666","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}
Non-Hermitian skin effect denotes the exponential localization of a large number of eigen-states in a non-Hermitian lattice under open boundary conditions. Such a non-Hermiticity-induced skin effect can offset the penetration depth of in-gap edge states, leading to counterintuitive delocalized edge modes, which have not been studied in a realistic photonic system such as photonic crystals. Here, we analytically reveal the non-Hermitian skin effect and the delocalized edge states in Maxwell's equations for non-Hermitian chiral photonic crystals with anomalous parity-time symmetry. Remarkably, we rigorously prove that the penetration depth of the edge states is inversely proportional to the frequency and the real part of the chirality. Our findings pave a way towards exploring novel non-Hermitian phenomena and applications in continuous Maxwell's equations.
{"title":"NON-HERMITIAN SKIN EFFECT AND DELOCALIZED EDGE STATES IN PHOTONIC CRYSTALS WITH ANOMALOUS PARITY-TIME SYMMETRY","authors":"Qinghui Yan, Hongsheng Chen, Yihao Yang","doi":"10.2528/pier21111602","DOIUrl":"https://doi.org/10.2528/pier21111602","url":null,"abstract":"Non-Hermitian skin effect denotes the exponential localization of a large number of eigen-states in a non-Hermitian lattice under open boundary conditions. Such a non-Hermiticity-induced skin effect can offset the penetration depth of in-gap edge states, leading to counterintuitive delocalized edge modes, which have not been studied in a realistic photonic system such as photonic crystals. Here, we analytically reveal the non-Hermitian skin effect and the delocalized edge states in Maxwell's equations for non-Hermitian chiral photonic crystals with anomalous parity-time symmetry. Remarkably, we rigorously prove that the penetration depth of the edge states is inversely proportional to the frequency and the real part of the chirality. Our findings pave a way towards exploring novel non-Hermitian phenomena and applications in continuous Maxwell's equations.","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84892866","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}
M. Durach, Felix Williamson, Jacob J. Adams, Tonilynn Holtz, P. Bhatt, R. Moreno, Franchescia Smith
We introduce a theory of optical responses of bianisotropic layers with arbitrary effective medium parameters, which results in generalized Fresnel-Airy equations for reflection and transmission coefficients at all incidence directions and polarizations. The poles of these equations provide explicit expressions for the dispersion of Fabry-Perot resonances and surface electromatic waves in bianisotropic layers and interfaces. The existence conditions of these resonances are topologically related to the zeros of the high-k characteristic function h(k) = 0 of bulk bianisotropic materials and taxonomy of bianisotropic media according to the hyperbolic topological classes [32, 33].
{"title":"ON FRESNEL-AIRY EQUATIONS, FABRY-PEROT RESONANCES AND SURFACE ELECTROMAGNETIC WAVES IN ARBITRARY BIANISOTROPIC METAMATERIALS","authors":"M. Durach, Felix Williamson, Jacob J. Adams, Tonilynn Holtz, P. Bhatt, R. Moreno, Franchescia Smith","doi":"10.2528/pier22020701","DOIUrl":"https://doi.org/10.2528/pier22020701","url":null,"abstract":"We introduce a theory of optical responses of bianisotropic layers with arbitrary effective medium parameters, which results in generalized Fresnel-Airy equations for reflection and transmission coefficients at all incidence directions and polarizations. The poles of these equations provide explicit expressions for the dispersion of Fabry-Perot resonances and surface electromatic waves in bianisotropic layers and interfaces. The existence conditions of these resonances are topologically related to the zeros of the high-k characteristic function h(k) = 0 of bulk bianisotropic materials and taxonomy of bianisotropic media according to the hyperbolic topological classes [32, 33].","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84102291","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}
|Free-electron radiation results from the interaction between swift electrons and the local electromagnetic environment. Recent advances in material technologies provide powerful tools to control light emission from free electrons and may facilitate many intriguing applications of free-electron radiation in particle detections, lasers, quantum information processing, etc. Here, we provide a brief overview on the recent theoretical developments and experimental observations of spontaneous free-electron radiation in various structured environments, including two-dimensional materials, metasurfaces, metamaterials, and photonic crystals. We also report the research progresses on the stimulated free-electron radiation that results from the interaction between free electrons and photonic quasi-particles induced by the external (cid:12)eld. Moreover, we provide an outlook of potential research directions for this vigorous realm of free-electron radiation. tailorable emission properties, free-electron radiations broad applications in the of particle
{"title":"FREE-ELECTRON RADIATION ENGINEERING VIA STRUCTURED ENVIRONMENTS","authors":"Hao Hu, Xiao Lin, Yu Luo","doi":"10.2528/pier21081303","DOIUrl":"https://doi.org/10.2528/pier21081303","url":null,"abstract":"|Free-electron radiation results from the interaction between swift electrons and the local electromagnetic environment. Recent advances in material technologies provide powerful tools to control light emission from free electrons and may facilitate many intriguing applications of free-electron radiation in particle detections, lasers, quantum information processing, etc. Here, we provide a brief overview on the recent theoretical developments and experimental observations of spontaneous free-electron radiation in various structured environments, including two-dimensional materials, metasurfaces, metamaterials, and photonic crystals. We also report the research progresses on the stimulated free-electron radiation that results from the interaction between free electrons and photonic quasi-particles induced by the external (cid:12)eld. Moreover, we provide an outlook of potential research directions for this vigorous realm of free-electron radiation. tailorable emission properties, free-electron radiations broad applications in the of particle","PeriodicalId":90705,"journal":{"name":"Progress in Electromagnetics Research Symposium : [proceedings]. Progress in Electromagnetics Research Symposium","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84102495","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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