Broadband Frequency Selective Surface

Abstract

Future communication satellites will use dichroic subreflectors to produce multiple focal regions from a single parabolic reflector. This additional focal region will allow for beams operating over different frequency bands to be produced by a single reflector and avoid the feed crowding or mechanical limitations current reflector antennas encounter. This paper presents parametric studies on a selected number of dichroic elements for possible use as a frequency selective subreflector. The theoretical and measured frequency response of tripoles and Jerusalem crosses are presented. This paper also addresses the design of multilayered dichroic panels to achieve improved gain slope and bandwidth. Designs capable of producing a 4:1 stopband and a 1.4:1 band separation for circular polarization and angles of incidence up to 40 degrees are shown.