Miniaturized band pass double-layered frequency selective superstrate for Wi-Max applications

In this paper, a double-layered frequency selective surface(FSS) superstrate was proposed. The unit cell of the proposed FSS consists of a square slot and a Jerusalem cross structure, which are printed on two sides of the substrate. It is designed on the FR4 dielectric substrate with a relative permittivity of 4.8, loss tangent 0.025 and a thickness of 1.6 mm. The proposed structure shows excellent band-pass response with respect to different incidence angles. It was found that a band pass response occur at the Wi-Max resonant frequency of 2.5 GHz. The overall bandwidth of the simulated structure is 2.35 GHz. Performance evaluated by CST computer simulation. FSS is a metallic screen with frequency selective properties which are used as a spatial filters through which EM energy with a specific frequency range may be propagated.