Study And Application Of Frequency Selective Surfaces

Over the past few decades,weapons such as missile,aircraft and reconnaissance satellite were using in morden war,and they are becoming a shrength force in the war.The radar on missile and aircraft are requiring better performance with the morden war come into information age.This causes a new contradiction: On the one hand,it is important for aircraft to detect a long-range threat;on the other hand,aircraft cannot be detected by enemy's radar.In order to solve this contradiction,frequency selective surfaces can be applied to the design of radome.The radome let electromagnetic wave in whit working frequency and it reflects electromagnetic wave with other frequency,so we achieve stealth effection.The study of frequency selective surfaces has become more and more popular.This paper discusses the design and simple application of frequency selective surfaces.Firstly,this paper introduces basic concept and working principle of the frequency selective surfaces,and then discusses relationship between unit size,unit space,medium,and incident wave and frequency response.The result are verified by simulation of the square ring slot unit and the Y-type unit.The method to achieve wider bandwith and sharp side performance is to cascade traditional two-dimensional frequency selective surface.Three-dimensional frequency selective surfaces were studied in this paper.This paper proposed a new 3D cross dipole based on 2D cross dipole,the frequency response under the condition of constant length and change was discussed.It is concluded that the 3D cross dipole can achieve a significant resonant frequency reduction by changing the arm length,and the 3D cross dipole's angle stability is better.In addition,other four 3D FSSs were design based on classic square ring patch,it is concluded that the second 3D FSS has lowest resonant frequency and the widest bandwidth.The three-dimensional frequency selective surface exhibits a larger design space.Finally,a simple frequency selective surface radome was designed,we optimize distance between radome and antenna.The conclusion is that the FSS radome can reduce the RCS of the antenna.