Millimeter-Wave SIW Filter Based on the Stepped-Impedance Face-to-Face E-Shaped DGSs

In this paper, a novel defected ground structure (DGS) is proposed and used to integrate into the metallic layer of millimeter-wave substrate integrated waveguide (SIW) to form bandpass filters. The lower stopband and upper stopband of the designed bandpass filter are achieved by, respectively, the nature cut-off frequency of SIW and the band notching property of the new proposed DGS. Numerical optimizations and experimental demonstrations are carried out to validate two of the proposed filters operating at different frequencies within Ka-band and the good agreements are obtained.