Design of Single-Layer Frequency Selective Surfaces for Multiband Reflector Antennas

Publisher Website
Google Scholar
Abstract
Future communication satellites will require single reflector antennas to operate at three or more frequency bands simultaneously. Frequency-selective surfaces are spatial filters which when incorporated as either flat or curved subreflectors into a reflector antenna allows it to operate at a number of different frequency bands. Multiple-layer frequency selective surfaces are currently being proposed for this application. In this paper two single-layer frequency selective surfaces are presented which offer potentially better crosspolar performance than multiple-layers together with reduced mechanical complexity. The surfaces are based on square loop elements and their transmission responses and crosspolar performances when measured in 45° plane dlplexers are discussed. Peak crosspolar levels of better than 30 dB are obtained. In addition models based on an equivalent circuit analysis are presented for the arrays. The calculated transmission responses are compared with experimental measurements for plane waves at normal incidence and TE and TH incidence at 45°. Computed and experimental results are in close agreement.