Design of waveguide filters by using genetically optimized frequency selective surfaces

A new optimization procedure suitable for the design of waveguide filters is presented. The filter structure consists of a frequency selective surface (FSS), placed on the transverse plane of a rectangular waveguide, so introducing a filtering behavior of the waveguide. Due to the boundary conditions imposed by the metallic waveguide walls, the FSS results to be infinite in extent, allowing the use of fast and efficient method of moments solvers to analyze its properties. A genetic algorithm (GA) has been adopted to optimize the filter performance. As an application, a waveguide filter has been designed to be used in an easy to fabricate and inexpensive very small aperture terminal (VSAT) feeder, for the ground station of an interactive satellite system.