Design of a modulated FSS subreflector for a dual-reflector system

This paper describes the design of a modulated FSS subreflector for a S/Ka-band Cassegrain dual-reflector system. The FSS subreflector separates the radiation from the S-band (2.0-2.3 GHz) and Ka-band (25.5-27.5 GHz).

To simplify the manufacturing of the subreflector, a conical FSS subreflector is considered. Instead of using a periodic FSS where all array elements are identical, a modulated FSS subreflector with varying sized array elements is considered. The FSS elements are optimized to emulate an axial displaced hyperboloid surface, thereby compensating for the non-optimal conical subreflector surface. In Ka-band, the optimized modulated FSS subreflector improves the peak gain of the antenna system with more 6 dBs compared to the use of a periodic FSS.

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Publication: EuCAP 2021