Highly Stable Frequency Selective Surface with Bandstop Characteristics for EMI Shielding for 28 GHz Applications

For 28 GHz millimeter-wave (mm-wave) electromagnetic interference (EMI) shielding applications, a bandstop frequency selective surface (FSS) design is proposed. The proposed FSS design consists of a meandered square-loop element and a parasitic ring. The meandered square loop is designed to get resonance in the desired frequency band, while the parasitic element is utilized to tune the response at 28 GHz. According to the results, the optimized FSS resonates for the 28 GHz frequency band, with a bandwidth of 10.175 GHz (25.4-35.575 GHz). Additionally, the proposed FSS’s stability study is conducted, and it is found to offer a stable response for both TE and TM polarizations up to 60° oblique incidence. In addition, the shielding effectiveness (SE) of the proposed FSS is evaluated, and reasonable results are observed.