Design of Balanced SIW Filter with Transmission Zeroes and Linear Phase

摘要

This paper provides a design method for balanced bandpass filters (BPFs) with high performance based on substrate integrated waveguide (SIW) structure. A novel balanced SIW filter with the characteristics of transmission zeroes, linear phase and wideband common-mode suppression is proposed. By analyzing the equivalent circuits of the proposed SIW filter under differential-mode (DM) and common-mode (CM) excitations, the DM transmission with CM suppression characteristic of the filter is demonstrated. The source-load coupled microstrip lines are introduced to realize the negative coupling and the design method for filters with source-load coupling is given. Good agreement is demonstrated between the simulated and the measured ones