Frequency selective surfaces(FSSs)play an important role in wireless systems as these can be used as filters,in isolating the unwanted radiation,in microstrip patch antennas for improving the performance of these ante...Frequency selective surfaces(FSSs)play an important role in wireless systems as these can be used as filters,in isolating the unwanted radiation,in microstrip patch antennas for improving the performance of these antennas and in other 5G applications.The analysis and design of the double concentric ring frequency selective surface(DCRFSS)is presented in this research.In the sub-6 GHz 5G FR1 spectrum,a computational synthesis technique for creating DCRFSS based spatial filters is proposed.The analytical tools presented in this study can be used to gain a better understanding of filtering processes and for constructing the spatial filters.Variation of the loop sizes,angles of incidence,and polarization of the concentric rings are the factors which influence the transmission coefficient as per the thorough investigation performed in this paper.A novel synthesis approach based on mathematical equations that may be used to determine the physical parameters ofDCRFSSbased spatial filters is presented.The proposed synthesis technique is validated by comparing results from high frequency structure simulator(HFSS),Ansys electronic desktop circuit editor,and an experimental setup.Furthermore,the findings acquired from a unit cell are expanded to a 2×2 array,which shows identical performance and therefore proves its stability.展开更多
A thick-screen frequency selective surface （FSS） has not only a broad bandwidth but also the advantages of overcoming the multilayer FSS shortcoming of complex structure and low transmittance of centre frequency due...A thick-screen frequency selective surface （FSS） has not only a broad bandwidth but also the advantages of overcoming the multilayer FSS shortcoming of complex structure and low transmittance of centre frequency due to the cascade of FSSs, and this means it could potentially be applied in a stealth curved streamlined radome. However, there is an unsteadiness of centre frequency in a wide range of incident angles and another unsteadiness of polarization in a big incident angle. In order to solve these problems, in this paper we provide a novel four-legged loaded element thick-screen FSS. The structure is analysed and simulated using the mode matching method and moment method. The centre frequency, the transmittance of centre frequency, and bandwidth of the structure are investigated when some parameters including the polarization at a big incident angle and the incident angles of TE ＆： TM waves are changed. The novel four-legged loaded element thick-screen FSS has better transmission properties with a better steadiness of polarization and incident angle independence. The novel structure of the four-legged loaded element thick-screen FSS provides a valuable reference for their application in a stealth curved streamlined radome.展开更多
A new frequency-selective surface(FSS)with loadings is introduced in this paper and analyzed by way of period moment methods(PMMs).The simulated results show that FSS may operate in different bands and especially gene...A new frequency-selective surface(FSS)with loadings is introduced in this paper and analyzed by way of period moment methods(PMMs).The simulated results show that FSS may operate in different bands and especially generate a large reduction in the resonant frequency for a fixed unit cell size through different loadings.This provides a new orientation in the development for FSS.Practical circuits are fabricated,and the measured results agree well with the simulated results.展开更多
It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas,such as the impedance matching,the radiation efficiency and the radiation pattern,are seriously affe...It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas,such as the impedance matching,the radiation efficiency and the radiation pattern,are seriously affected by the metallic surface.This paper presents the characteristics of the dipole-like antennas of ultra high frequency(UHF) radio frequency identification(RFID) tags that are placed close to metallic surfaces.The finite element method(FEM) and method of moment(MoM) were used to simulate the changes of the antenna parameters near the metallic surface.Two typical dipole-like antennas close to the metallic surface,a closed loop antenna and a loaded meander antenna,were modeled,and the performance was evaluated.Experiment was carried out and the results were in good agreement with the simulation,showing that a distance of 0.05λ～0.1λ(λ is the free space wavelength) from the metallic surface could make the dipole-like UHF RFID tag performance be acceptable.展开更多
文摘Frequency selective surfaces(FSSs)play an important role in wireless systems as these can be used as filters,in isolating the unwanted radiation,in microstrip patch antennas for improving the performance of these antennas and in other 5G applications.The analysis and design of the double concentric ring frequency selective surface(DCRFSS)is presented in this research.In the sub-6 GHz 5G FR1 spectrum,a computational synthesis technique for creating DCRFSS based spatial filters is proposed.The analytical tools presented in this study can be used to gain a better understanding of filtering processes and for constructing the spatial filters.Variation of the loop sizes,angles of incidence,and polarization of the concentric rings are the factors which influence the transmission coefficient as per the thorough investigation performed in this paper.A novel synthesis approach based on mathematical equations that may be used to determine the physical parameters ofDCRFSSbased spatial filters is presented.The proposed synthesis technique is validated by comparing results from high frequency structure simulator(HFSS),Ansys electronic desktop circuit editor,and an experimental setup.Furthermore,the findings acquired from a unit cell are expanded to a 2×2 array,which shows identical performance and therefore proves its stability.
文摘A thick-screen frequency selective surface （FSS） has not only a broad bandwidth but also the advantages of overcoming the multilayer FSS shortcoming of complex structure and low transmittance of centre frequency due to the cascade of FSSs, and this means it could potentially be applied in a stealth curved streamlined radome. However, there is an unsteadiness of centre frequency in a wide range of incident angles and another unsteadiness of polarization in a big incident angle. In order to solve these problems, in this paper we provide a novel four-legged loaded element thick-screen FSS. The structure is analysed and simulated using the mode matching method and moment method. The centre frequency, the transmittance of centre frequency, and bandwidth of the structure are investigated when some parameters including the polarization at a big incident angle and the incident angles of TE ＆： TM waves are changed. The novel four-legged loaded element thick-screen FSS has better transmission properties with a better steadiness of polarization and incident angle independence. The novel structure of the four-legged loaded element thick-screen FSS provides a valuable reference for their application in a stealth curved streamlined radome.
基金This work was supported by the Major Fundamental Preliminary Research Foundation for National Security(No.51307).
文摘A new frequency-selective surface(FSS)with loadings is introduced in this paper and analyzed by way of period moment methods(PMMs).The simulated results show that FSS may operate in different bands and especially generate a large reduction in the resonant frequency for a fixed unit cell size through different loadings.This provides a new orientation in the development for FSS.Practical circuits are fabricated,and the measured results agree well with the simulated results.
基金Project (No.2006C12051) supported by the Science and Technology Plan of Zhejiang Province,China
文摘It is a challenge for passive RFID tags to be mounted on the surface of metal because the parameters of tag antennas,such as the impedance matching,the radiation efficiency and the radiation pattern,are seriously affected by the metallic surface.This paper presents the characteristics of the dipole-like antennas of ultra high frequency(UHF) radio frequency identification(RFID) tags that are placed close to metallic surfaces.The finite element method(FEM) and method of moment(MoM) were used to simulate the changes of the antenna parameters near the metallic surface.Two typical dipole-like antennas close to the metallic surface,a closed loop antenna and a loaded meander antenna,were modeled,and the performance was evaluated.Experiment was carried out and the results were in good agreement with the simulation,showing that a distance of 0.05λ～0.1λ(λ is the free space wavelength) from the metallic surface could make the dipole-like UHF RFID tag performance be acceptable.
