Investigation of the RCS for finite bandpass frequency selective surface

Frequency selective surface (FSS) with finite size behaves differently compared to an ideal infinite one, due to the influence of fringe effect, while there exist little study concerning this subject. RCS radiation can serve as a critical indicator of the FSS performance which can quantitatively reveal the mechanism of the fringe effect. This paper presents the study of RCS for FSS with finite structures. RCS for different sized FSS with different configurations under plane wave illumination are studied qualitatively. The result reveals the frequency selectivity and fringe effect of finite FSS. Quantitative functional relations between fringe effect and dimension of FSS are first summarized for monolayer FSS. A new case is then picked and tested to verify the validity of the functional relations. The relations are also extended to multilayer FSS. It turns out that the relations are general properties of finite FSS excited by plane waves.