An inductive dichroic surface for reflector antennas

An inductive dichroic surface is presented for use as a sub-reflector in a tri-band reflect antenna. Such antennas are often used for satellite communications systems. The surface is designed to be reflective in the frequency range 10.7-12.75 GHz, situated in the Ku band, and minimal transmission loss at the two Ka sub-bands 17.3-20.2 GHz and 28.295-30 GHz. The large bandwidths of operation in the transmission bands and the requirement of fast roll-off characteristics constitute the challenging aspects of the design of this frequency selective surface (FSS). Simulated results for the preferred design are given, fulfilling the reflectivity and transmission specifications required in the different frequency bands.