An Intelligent Non-Trial-and-Error Design Method for Double Screen Frequency Selective Surfaces

An intelligent design method of double screen frequency selective surfaces (FSSs) is addressed in this paper. The employed unit cell is composed of two metallic screens, which are printed on both sides of a substrate. The presented non-trial-and-error approach is investigated based on the separate design of each screen. With the help of some physical intuition and an equivalent circuit model, it is shown that the conventional use of complement geometries restricts the final desired filtering response. Therefore, unlike the previous studies, the metallic screens are not geometrically complementary in this paper. An excellent agreement between the full-wave simulations and corresponding equivalent circuit models has been observed. Using standard lumped elements, a highly selective miniaturized FSS (0.06λ0 ~ 0.08λ0) with two closely-spaced pass bands is designed, for GSM and WLAN frequencies. Simulation results show a dual-polarized characteristic with a good angular stability performance for the proposed structure.