We propose an ultra-broadband and polarization independent planar absorber comprising multilayered graphene. The bandwidth of the proposed absorber is extended by increasing the number of layers of graphene, and it is...We propose an ultra-broadband and polarization independent planar absorber comprising multilayered graphene. The bandwidth of the proposed absorber is extended by increasing the number of layers of graphene, and it is polarization independent due to its symmetrical unit structure. The full wave simulation results show that an absorber with three graphenebased layers can efficiently harvest an electromagnetic wave with random polarization from 17.9 GHz to 188.7 GHz（i.e.,covering frequency regimes from K to D bands and relative bandwidth of - 165%）. The physical absorption mechanism of ultra-broadband absorption has been elaborated upon using the destructive interference method and multiple resonances approach in a multilayered medium. The proposed absorber can be used in many applications such as medical treatment,electromagnetic compatibility, and stealth technique.展开更多
An ultra-wideband pattern reconfigurable antenna is proposed.The antenna is a dielectric coaxial hollow monopole with a cylindrical graphene-based impedance surface coating.It consists of a graphene sheet coated onto ...An ultra-wideband pattern reconfigurable antenna is proposed.The antenna is a dielectric coaxial hollow monopole with a cylindrical graphene-based impedance surface coating.It consists of a graphene sheet coated onto the inner surface of a cylindrical substrate and a set of independent polysilicon DC gating pads mounted on the outside of the cylindrical substrate.By changing the DC bias voltages to the different gating pads,the surface impedance of the graphene coating can be freely controlled.Due to the tunability of graphene＇s surface impedance,the radiation pattern of the proposed antenna can be reconfigured.A transmission line method is used to illustrate the physical mechanism of the proposed antenna.The results show that the proposed antenna can reconfigure its radiation pattern in the omnidirectional mode with the relative bandwidth of 58.5% and the directional mode over the entire azimuth plane with the relative bandwidth of 67%.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61661012,61461016,61361005,and 61561013)the Natural Science Foundation of Guangxi,China(Grant No.2017JJB160028)+1 种基金the Program for Innovation Research Team of Guilin University of Electronic Technology,Chinathe Dean Project of Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing,China
文摘We propose an ultra-broadband and polarization independent planar absorber comprising multilayered graphene. The bandwidth of the proposed absorber is extended by increasing the number of layers of graphene, and it is polarization independent due to its symmetrical unit structure. The full wave simulation results show that an absorber with three graphenebased layers can efficiently harvest an electromagnetic wave with random polarization from 17.9 GHz to 188.7 GHz（i.e.,covering frequency regimes from K to D bands and relative bandwidth of - 165%）. The physical absorption mechanism of ultra-broadband absorption has been elaborated upon using the destructive interference method and multiple resonances approach in a multilayered medium. The proposed absorber can be used in many applications such as medical treatment,electromagnetic compatibility, and stealth technique.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61661012,61461016,and 61361005)the Natural Science Foundation of Guangxi,China(Grant Nos.2015GXNSFBB139003 and 2014GXNSFAA118283)+1 种基金Program for Innovation Research Team of Guilin University of Electromagnetic Technology,Chinathe Dean Project of Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing,China
文摘An ultra-wideband pattern reconfigurable antenna is proposed.The antenna is a dielectric coaxial hollow monopole with a cylindrical graphene-based impedance surface coating.It consists of a graphene sheet coated onto the inner surface of a cylindrical substrate and a set of independent polysilicon DC gating pads mounted on the outside of the cylindrical substrate.By changing the DC bias voltages to the different gating pads,the surface impedance of the graphene coating can be freely controlled.Due to the tunability of graphene＇s surface impedance,the radiation pattern of the proposed antenna can be reconfigured.A transmission line method is used to illustrate the physical mechanism of the proposed antenna.The results show that the proposed antenna can reconfigure its radiation pattern in the omnidirectional mode with the relative bandwidth of 58.5% and the directional mode over the entire azimuth plane with the relative bandwidth of 67%.
