Analysis And Design Of Four-Band Frequency Selective Surface Subreflector Antenna

Frequency selective surface (FSS) technologies and its applications in multiband subreflector antenna are investigated in detail. The concept and mechanism of frequency selective surface are introduced firstly. Influencing factors, such as element, lattice, substrate and incidence wave, are discussed. Field equation for frequency selective surface is derived in spectral domain and solved by the Galerkin moment method. Based on idea and procedure for designing FSS, two structures of single- and double-screen are presented for four-band subreflector antenna application. In both designs, double-square-loop (DSL) patch is used as FSS element. Numerical results show that the designed subreflector with double FSS screens can meet the requirements of return and insert losses at normal incidence and in the case of small incidence angle. Calculated results by spectral domain method are found to be in a good agreement with its counterparts obtained by Ansoft Designer.