Design of Substrate Integrated Waveguide (SIW) Elliptic Filter with Novel Coupling Scheme

Abstract

A novel fourth-order substrate integrated waveguide (SIW) quasi-elliptic filter with novel coupling scheme is presented in this paper. A microstrip resonator (MR) with two grounded ends is introduced into the filter design. It not only acts as a resonator, but also brings different direct couplings between MR and SIW resonator. Then, quasi-elliptic response can be obtained easily. The proposed filter has better frequency selectivity than the conventional third-order SIW filter. A filter sample is fabricated on single-layer printed circuit board (PCB) technology. Good agreements are obtained between its measured- and simulated S-parameters.