Compact Substrate Integrated Waveguide Transversal Filter with Microstrip Dual-Mode Resonator

Abstract

A compact substrate integrated waveguide (SIW) transversal filter using microstrip dual-mode resonator is proposed, with its coupling scheme given to predict its desired performance. The microstrip dual-mode resonator is introduced to achieve compact size, which is etched on the top metal layer of the SIW cavity. An additional transmission zero, contributed by bypass coupling due to the higher order mode of SIW cavity, is used to suppress its first spurious passband. A filter sample was fabricated using standard printed circuit board (PCB) technology, with good agreements obtained between its measured and simulated S–parameters.