Broadband substrate integrated waveguide filters with defected ground structure

Abstract

This paper presents a scheme for designing broadband filters based on the substrate integrated waveguide (SIW) cavity with defected ground structures (DGS).The proposed DGS split-ring resonator (SRR) is developed from micro-strip SRR. Through the cross coupling resonator with source-load coupling, a compact broadband filter with three transmission zeros in the stop-band is realized and measured. According to the test, such filter has a 27% fractional bandwidth with 26.6GHz center frequency. Furthermore, another broadband filter based on this method is illustrated and simulated to suppress the nearby spurious band by double SIW cavities.