A generalized scattering matrix analysis for cascading FSS of different periodicities

A generalized scattering matrix for cascading frequency-selective surfaces (FSSs) of different periodicities is developed by studying the interaction of the harmonics when scattered between two screens of different periods. It is noted that the new system, formed by stacking two (or more) screens of different periods, will have a scattered spectrum which is, in general, more densely packed than the spectra of any of the individual component screens. Using this approach, one can apply the old cascading equations to generate composite systems matrices (for FSSs radomes). The procedure was carried out for a system of two stacked strip gratings with different periodicities.<>