Design of a cascaded frequency selective surface as a dichroic subreflector

The frequency selective surface (FSS) is often used as a filter for electromagnetic radiation to separate the S- and K-band feed in a communication satellite. The problem of synthesizing such a multifrequency-band FSS as a subreflector in a communication satellite antenna system that covers the frequency range of 2-30 GHz is considered. The reflection and transmission properties of FSS screens are calculated using the spectral-Galerkin method in conjunction with the cascading technique. The frequency responses of one-layer, two-layer, and three-layer screens are shown. The frequency response of a four-legged FSS was also computed. It is shown that the square-aperture-type FSS performs better than the four-legged configuration.<<ETX>>