Waveguide dual-mode filter in extended box topology for general asymmetric transfer characteristics

In this paper, waveguide dual-mode bandpass filter in extended box coupling topology is for the first time designed and presented. By configuring in this topology, the dualmode filter can realize independently-controllable transmission zeroes which may be difficult for a filter in conventional cascade-quartet (CQ) topology to realize. An asymmetric 6-pole circular waveguide dual-mode bandpass filter with two transmission zeroes located on the upper rejection band is full-wave prototyped and manufactured. The measurement result agrees well with the circuit model prediction, which successfully verifies the validity and advantages of this filter design.