A tri-band inductive frequency selective surface sub-reflector for satellite communications systems

An inductive dichroic surface is presented for use as a sub-reflector in a tri-band satellite communications antenna system. The surface is designed to be reflective in the frequency range 10.7-12.75 GHz, situated in the Ku band, and transmissive 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). The FSS development process is reported in detail followed by the presentation of performance of the final design fulfilling reflectivity and transmissivity specifications in the different frequency bands.