A Novel Miniaturized Dual-band SIW Filter with Controllable Bandwidth

The paper proposes a miniaturized dual-mode filter with controllable center frequencies by cascading two 90° fan-shaped SIW dual-mode resonators (FSSIWRs) to form a doublet topology. Two passbands of the filter are obtained using the fundamental mode TM 101 and higher order mode TM 201 . Two posts are added at the 45° direction of the dual-mode SIW cavity to realize diagonal perturbation. The posts can not only split the degenerate modes, but also offset the frequency of the first passband without affecting the second passband in the meantime. The simulated results show that the filter achieves a return loss of the two passbands higher than 17 dB. Both simulated central frequencies are located at 7.67 and 10.3 GHz, corresponding to the 3 dB bandwidths of 430MHz, respectively.