This paper presents a simple perturbation technique using an off-centered metal cylinder in rectangular waveguide cavity to realize a triple-mode wideband bandpass filter. A TM mode along with two degenerate hybrid modes namely HM+ and HM-, are excited by an off-centered perturbation in a single rectangular metal cavity. The filter operates at central frequency of 2.4 GHz with fractional bandwidth of 58%. Finally, the filter is fabricated using brass. Measured results are in good agreement with the simulated results.
