The Frequency Selective Surface Analysis And Optimization Design

In this thesis, Spectral method is used to analyse the scattering characteristic of Frequency Selective Surfaces(FSS). Firstly, two fundamental types of FSS in free space are studied, and their reflecting or transmission coefficient are solved. Secondly, the frequency response of FSS switched between dielectric is discussed. As a following step, the spectral method is reviewed intensively, including how to build the spectral equation and how to use Galerkin method solving the inducting current and scattering field. In order to design FSS properly, different programs for different types of FSS need to be developed and the influence of each parameters need to be understood beforehand. And programs for cross dipoles, ring aperture and Y aperture are given because they are used widely in application. As for other typical and regular types, full domain basis functions are given and can be used to solve their frequency response by spectral method. And then the inflence of parameters is discussed and design strategy and flowing chart are presented. For the purpose of optimising FSS design, Genetic algorithm (GA) is introduced. As an effective parallel researching method, it is very suitable for the FSS design problems. In the last chapter, the application of GA is reviewed and the flow chart for optimising FSS design is given.In this thesis, not only the fundamental principle of FSS but also the computationl examples are presented. I hope it will be helpful for the researchers on FSS.