Planar single-/dual-band bandpass filters based on new perturbed multi-mode SIW circular cavity.

In this paper, new single- and dual-band bandpass filters are implemented based on the perturbed multi-mode substrate integrated waveguide (SIW) circular cavity. For the single-band filter, the TM 010 mode, TM 110 A mode, and TM 210 A mode are simultaneously utilized to realize the triple-mode resonance response, of which both the bandwidth and central frequency can be flexibly adjusted by allocating the perturbation position properly. Meanwhile, for the dual-band operation, the TM 010 mode, TM 110 A mode, and TM 210 A mode are arranged to realize the lower passband, whereas the TM 210 B and TM 020 modes are excited to generate the upper passband. The working principle of the filters' coupling topology is explained in detail. For concept verification, both the triple-mode single-band and multi-mode dual-band filters are designed, manufactured and measured, with the measurement results are separately in good agreement with the corresponding simulations. [ABSTRACT FROM AUTHOR]