Compact Substrate Integrated Waveguide Bandstop Filter Based On CSRRs

A compact substrate integrated waveguide (SIW) bandstop filter (BSF) based on complementary split-ring resonators (CSRRs) is proposed in this paper. The CSRRs is proven to have bandstop behavior and the characteristics of CSRR and double-CSRRs are studied firstly. Based on the analysis of CSRRs, the size, opening directions and spacing between CSRRs can be obtained. Then, a BSF is realized using four CSRRs with different opening directions etched on the top metal. Moreover, the bandwidth of stopband can be adjusted by tuning the dimensions of CSRRs and the coupling strength between them. For demonstration, the proposed filter is designed, fabricated and measured, and the measurement results verify the feasibility of the design.