Design and Analysis of Compact SIW Bandpass Filter using DGS-DMS Technique for Satellite Applications

This letter proposes a new compact substrate integrated waveguide based bandpass filter for satellite application. First SIW BPF is designed by tapered via transition to provide a smooth transition from microstrip line to SIW cavity with minimal reflection and better S11 performance. The stop band performance of the proposed filter is improved by introducing a two square head DGS connected by U-slot on the bottom ground plane which introduces transmission zeros in upper stopband. DMS is made by etching two horizontal slots on the top of the SIW cavity in order to provide finite passband and to suppress undesired harmonic response. The filter with center frequency of 7GHz and fractional bandwidth of 2.8% is developed on the Rogers substrate with dielectric constant of 3.5 and substrate thickness of 0.5mm. By combining the concept of DGS-DMS, the proposed filter exhibits very low insertion loss of 0.02dB, return loss >20dB and compact size. The structure is simulated and analyzed by using Advanced Design softwar