A compact C-band bandpass filter using one eighth substrate integrated waveguide resonator

In this paper, a triangular shaped resonator which is one eighth of a square substrate integrated waveguide (SIW) cavity is used to design a novel miniaturized C-band bandpass filter. With the proposed one eighth SIW resonator (ESIWR) and new coupling structures, a conventional SIW filter can be reduced in size by about 87.5%. A four pole ESIWR filter with a center frequency of 5.8GHz and a fractional bandwidth of 8% is implemented. Good agreement between simulated and measured results demonstrates the validity of the proposed method.