Non-planar Frequency Selective Surface based Bandstop Filter for Electromagnetic Shielding

This paper presents a frequency selective surface (FSS) based bandstop filter design that has been implemented on different non-planar surfaces for electromagnetic (EM) shielding applications. The unit cell of the FSS features a metallic annular ring geometry printed on a polylactic acid (PLA) dielectric material periodically. The structure has initially been studied on a planar surface and a bandstop response is observed ranging from 8.56 to 11.4 GHz, with the resonance occurring at 10 GHz. The FSS unit cell has then been wrapped on two distinct non-planar surfaces (frustum and hemisphere) and their shielding characteristics are individually studied using the multilevel fast multipole method (MLFMM). The responses observed for both non-planar surfaces show similar behaviors as that of the planar surface, thereby validating the proposed conformal FSS structure.