A novel dual-band bandpass filter using a single perturbed substrate integrated waveguide cavity

A novel dual-band bandpass filter based on the multimodes in a single perturbed substrate integrated waveguide (SIW) cavity is proposed. Metallized via-holes are introduced to serve as perturbations to shift and control the first four resonant modes and divide them into two groups. The perturbed TE101 and TE102 modes lead to the first passband while the perturbed TE201 and TE202 modes constitute the second passband. Furthermore, by moving the via-holes along the diagonal line of the SIW cavity, the first passband can be tuned independently while the second passband is fixed. A prototype filter operating at 9.22 GHz and 11.30 GHz is designed and fabricated. Measured and simulated results are presented to validate the proposed design concept of the dual-band filter.