Miniaturized substrate integrated waveguide (SIW) bandpass filter loaded with double-sided-complementary split ring resonators (DS-CSRRs)

In this paper, we present an effective technique to miniaturize a substrate integrated waveguide (SIW) bandpass filter by using a double-sided complementary split ring resonator (DS-CSRR). With the proposed technique, the proposed DS-CSRR SIW filter provides a lower resonance frequency compared to a conventional complementary split ring resonator (CSRR) SIW filter thanks to the coupling effect between CSRR of top and bottom plates. The characteristic of the DS-CSRR is modeled by an LC resonance circuit and its transfer function shows bandpass frequency response. Both circuit and full-wave simulated frequency responses confirm the theory of the proposed technique and good agreement is achieved with the experimental results.