Improvement of SIW filter upper stopband performance using bypass coupling substrate integrated circular cavity (SICC)

Abstract

A novel method of using bypass coupling SICC resonator to generate transmission zeros (TZs) in filter stopband to improve upper stopband attenuation is presented. A SIW quasi-elliptic function filter with bypass coupling SICC resonators is designed and fabricated to validate the method. The results show the method is effective to improve the filter stopband performance.