Crosspolar levels of ring arrays in reflection at 45° incidence: influence of lattice spacing

Abstract

The importance of the lattice spacing is illustrated by the performance of three arrays of simple rings arranged on square lattices with 2r/D = 0.61, 0.64 and 0.87, used as frequency selective surfaces in a 45° incidence diplexer. Peak crosspolar levels were about −35 dB for the closely spaced lattice, rising to −24 dB at the upper band edge for the widest spacing, for which the reflection band centres were not coincident for E- and H-plane incidence.