Frequency Selective Surface Technology And Its Application In The Design Of Radome

Due to the unique performance and applications,a large number of frequency selective surface(FSS)studies have been carried out in various fields.In addition,the frequency selective surface with the role of microwave spatial filtering has been widely used since 2000,and it has gradually become the focus of researchers.Its basic theory comes from the development of the gate.From the periodic units,the resonant frequency of a certain bandwidth corresponding to cell size,respectively,reflected in the reflection and transmission characteristics to create the effect of filtering.Multi-band,based on three-dimensional structure and miniaturization FSS design is the research trends of domestic and foreign experts in recent years.This paper summarizes the commonly effective calculation methods of frequency selective surface,and uses the equivalent circuit method to analyze the frequency selective surface of the typical structure shapes.The principle of the frequency selective surface is explained in detail,the equivalent circuit model is obtained by the works,and the relationship is deduced theoretically between the structural unit parameters setting and frequency selective surface characteristics.The comparison of using equivalent circuit calculation and finite element software simulation verifies the results.Secondly a new structure based on square ring and three-pole loading are presented.The performance of the new structure Frequency Selective Surface(FSS)was studied.The feasibility of the application of the FSS was discussed.The wave-transparent rate through this structure is given,when plane wave incident.The results of different incidence angles of the plane wave were compared.The stability of this structure,different polarized wave incidents,has also been studied.Simulation results show that this structure is very stable.From the study,the FSS designed with this structure showed good band pass characteristics and oblique incidence stability.It is important that FSS has little effect on the performance of a circularly polarized antenna.Next,two applications which were carried out to verify the feasibility of the FSS structure are using the FSS as the high impedance surface to design absorbing material and as the radome to reduce the antenna Radar Cross Section(RCS).The wave-transparent rate of the FSS is given when a plane wave is incident at some angles.Simulation results show that the performance of the FSS is stable.In the first application,the absorbing material only designed with the FSS structure and FR4 is thinner than the traditional absorbing material,the total thickness is low to 3.6mm.Finally,a new frequency selection radome is designed and used in the area of radar cross section(RCS)reduction Frequency Selective Radome not only can reduce the RCS but also can resist external interference to maintain a good working environment for antenna.In the following content,we use an ideal model of antenna and radome system to discuss the influence of the Frequency Selective Radome on the conformal antennas.The operating frequency of the curved radome is determined by a variable dipole antenna.The results of RCS and antenna performance were compared between cylindrical conformal antenna array with radome or not.It's worth noting that the FSS radome has little effect on the performance of conformal antenna array,moreover it has a significant RCS reduction in stop band.Simulation results show the FSS can be used to design efficient electromagnetic absorber and radome that all can be applied in RCS reduction.