A dualband terahertz(THz) absorber including periodically distributed cross-shaped graphene arrays and a gold layer spaced by a thin dielectric layer is investigated.Numerical results reveal that the THz absorber disp...A dualband terahertz(THz) absorber including periodically distributed cross-shaped graphene arrays and a gold layer spaced by a thin dielectric layer is investigated.Numerical results reveal that the THz absorber displays two perfect absorption peaks.To elucidate the resonant behavior, the LC model is introduced to fit the spectra.Moreover, the strength and linewidth of the absorption peak can be effectively tuned with structural parameters and the relaxation time of graphene.Owing to its rotational symmetry, this THz absorber exhibits polarization insensitivity.Our designed absorber is a promising candidate in applications of tunable optical sensors and optical filters.展开更多
A compact low-profile dual-band Circularly Polarized(CP)microstrip antenna is proposed for the Bei Dou Navigation Satellite System(BDS).To achieve dual-band functionality,a single-layer multimode design is employed,in...A compact low-profile dual-band Circularly Polarized(CP)microstrip antenna is proposed for the Bei Dou Navigation Satellite System(BDS).To achieve dual-band functionality,a single-layer multimode design is employed,incorporating F-,L-,and T-shaped slots at the corners for CP performance.Additionally,a Defected Ground Structure(DGS)is implemented to further enhance the antenna's efficiency.A detailed parameter analysis is conducted to optimize the antenna's size and performance balance.After optimization,the final dimensions of the antenna are minimized while still meeting the design requirements.The prototype of the optimized antenna is fabricated and tested,demonstrating coverage of frequency bands from 1.182 GHz to 1.217 GHz and 1.547 GHz to 1.569 GHz.The antenna effectively supports dual-band CP for B1I and B2b frequency bands.A performance metric,the Ratio of relative Bandwidth to Volume(RBV),is introduced to evaluate the antenna's efficiency.Compared to similar designs,the proposed antenna offers a smaller size without sacrificing performance,making it well-suited for BDS airborne applications.展开更多
The design and development of a proximity fed dualband microstrip patch antenna based on David fractal geometry are presented. David fractal microstrip antenna offers good performance in the 1.754 - 1.816 GHz and 3.37...The design and development of a proximity fed dualband microstrip patch antenna based on David fractal geometry are presented. David fractal microstrip antenna offers good performance in the 1.754 - 1.816 GHz and 3.37 - 3.415 GHz bands and is suitable for GSM 1800, WiMAX applications. The use of David fractal geometry offers miniaturization of the antenna structure. The proposed first iteration fractal configuration is fabricated and measured results along with simulation results are presented. Good radiation patterns and moderate gain are also obtained.展开更多
基金Project supported by the Key Science and Technology Research Project of Henan Province,China(Grant Nos.162102210164 and 1721023100107)the Natural Science Foundation of Henan Educational Committee,China(Grant No.17A140002)
文摘A dualband terahertz(THz) absorber including periodically distributed cross-shaped graphene arrays and a gold layer spaced by a thin dielectric layer is investigated.Numerical results reveal that the THz absorber displays two perfect absorption peaks.To elucidate the resonant behavior, the LC model is introduced to fit the spectra.Moreover, the strength and linewidth of the absorption peak can be effectively tuned with structural parameters and the relaxation time of graphene.Owing to its rotational symmetry, this THz absorber exhibits polarization insensitivity.Our designed absorber is a promising candidate in applications of tunable optical sensors and optical filters.
基金co-supported by the Natural Science Foundation of Tianjin,China(No.21JCZDJC00860)the Civil Aviation Security Capacity Building Funding Project,China(No.2020[142])。
文摘A compact low-profile dual-band Circularly Polarized(CP)microstrip antenna is proposed for the Bei Dou Navigation Satellite System(BDS).To achieve dual-band functionality,a single-layer multimode design is employed,incorporating F-,L-,and T-shaped slots at the corners for CP performance.Additionally,a Defected Ground Structure(DGS)is implemented to further enhance the antenna's efficiency.A detailed parameter analysis is conducted to optimize the antenna's size and performance balance.After optimization,the final dimensions of the antenna are minimized while still meeting the design requirements.The prototype of the optimized antenna is fabricated and tested,demonstrating coverage of frequency bands from 1.182 GHz to 1.217 GHz and 1.547 GHz to 1.569 GHz.The antenna effectively supports dual-band CP for B1I and B2b frequency bands.A performance metric,the Ratio of relative Bandwidth to Volume(RBV),is introduced to evaluate the antenna's efficiency.Compared to similar designs,the proposed antenna offers a smaller size without sacrificing performance,making it well-suited for BDS airborne applications.
文摘The design and development of a proximity fed dualband microstrip patch antenna based on David fractal geometry are presented. David fractal microstrip antenna offers good performance in the 1.754 - 1.816 GHz and 3.37 - 3.415 GHz bands and is suitable for GSM 1800, WiMAX applications. The use of David fractal geometry offers miniaturization of the antenna structure. The proposed first iteration fractal configuration is fabricated and measured results along with simulation results are presented. Good radiation patterns and moderate gain are also obtained.
