Design of aperiodic frequency selective surfaces for compact quasi-optical networks

The design of an aperiodic frequency selective surface (FSS) for compact quasi-optical networks is presented in this paper. Using a newly developed Physical Optics (PO) method in conjunction with a direct optimisation approach where all elements are simultaneously optimised, an FSS with an aperiodic element layout operating in several discrete bands over the frequency range 23–230 GHz has been designed. The design procedure and a comparison with an existing periodic FSS designed to meet the same specifications are provided. This comparison indicates that enhanced performance can be obtained using an aperiodic FSS compared to a periodic FSS.