Dual‐band substrate integrated waveguide bandpass filter utilising complementary split‐ring resonators

Abstract

A novel dual‐band substrate integrated waveguide (SIW) bandpass filter (BPF) based on complementary split‐ring resonators (CSRRs) is proposed. It consists of an SIW dual‐mode cavity loaded by two additional CSRRs on its top layer. Both TE 102 and TE 201 modes in the cavity can be excited by the proper positions of the feeding lines. Two additional CSRRs are etched on the top layer coupled with the TE 102 and TE 201 modes, respectively, to achieve the dual‐frequency operation. Four transmission zeros are generated in the vicinity of the passbands to improve the selectivity. To validate the design concept, a dual‐band SIW BPF operating at 7.89 and 8.89 GHz is designed, simulated and measured. The measured results are in good agreement with the simulations.