Compact Third-Order Bandpass Frequency Selective Surface with Wide Spurious-Suppression Bandwidth

A compact third-order bandpass frequency selective surface (FSS) with high selectivity and wide spurious-suppression bandwidth characteristics is presented. The proposed multi-layer FSS filter operating in the C-band, is composed of three Jerusalem Cross (JC) periodic array layers coupled together through periodic square aperture layers. The wide rejection band is obtained by incorporating bandstop JC layers that are designed to suppress spurious responses. The analysis of the design based on its equivalent circuit model (ECM) shows that the proposed FSS design can be synthesized with inductively coupled bandpass resonators from filter theory. To demonstrate its superior response, the proposed third-order FSS is compared through full wave simulation with its counterpart [5], which uses complementary JC layers that behave as parallel LC bandpass resonators.