Design of SIW Bandpass Filter Based on Asymmetric Complementary Split Ring Resonators

Compact substrate integrated waveguide (SIW) bandpass filters are proposed in this article based on the novel complementary split ring resonator (CSRR). The single stage SIW bandpass filter (BPF) with face to face orientation of outer ring is analyzed, and then the similar two stage configuration is analyzed. The substrate material used to manufacture the filter is RT/Duroid 4003, which has a relative tolerance of 3.55 and a height of 0.508 mm. The proposed two stage SIW BPF has a center frequency of 3.57 GHz and a 3-dB bandwidth of 0.23 GHz, which provides better selectivity, bandwidth and stopband performance compared to conventional filters.