A Compact Wideband DGS Bandpass Filter Based on Half Mode Substrate Integrated Waveguide Technology.

In this paper a defected ground structure (DGS) bandpass filter based on half mode substrate integrated waveguide (HMSIW) technology is proposed. We used vertical double circle complimentary split ring resonator (CSRR) as DGS etched on the top plane of the SIW cavity to constitute a multiple mode resonator and dumbbell DGS etched on the ground plane of the SIW cavity for enhance the filter performance. The taper line is used for transition between microstrip to SIW The simulation results obtained by CST and HFSS show that the proposed filter has a large transmitted bandwidth from 6.2 to 12.7 GHz. The higher simulated insertion loss is about -0.5 dB and the lower return loss is about -48 dB. The size of the designed filter is 60 × 9.8 mm2 which make it more compact compared to other published research works with a size reduction of about 50%. Good rejection are achieved under 6 GHz and upper 13 GHz. The good calculation of taper, the empirical parameters of the filter and the use many DGS cells in the bottom plane allowed us to obtain the good results. Good agreement between CST and HFSS simulation results. [ABSTRACT FROM AUTHOR]