Dual‐mode dual‐band bandpass filter design utilising cylindrical TM‐mode cavities

This letter presents the design of a novel dual-mode dual-band bandpass filter that utilises TM210 and TM020 modes cylindrical cavity resonators for millimetre-wave operation when fed with standard WR-10 waveguide ports. In this manner, two selected are demonstrated as single propagation path fixed dual-passband responses without need perturbations or tuning screws. The passbands designated centre frequencies at approximately 102.8 110.9 GHz exhibit four-pole Chebyshev characteristic in each passbands, which separated by transmission zero location. Simulated measured results prototype presented to verify design.