A method of implementing transmission zeros by partial irises in filter design

Abstract

An iris band-reject element used to produce the transmission zero (TZ) in a waveguide bandpass filter is proposed and analyzed. This element is an partial iris in a rectangular waveguide. It's found that the partial iris with certain height can produce a proper TZ and it can be applied in filter design to improve the stopband's performance. An improved waveguide type bandpass filter of Ka band with the band-reject irises is simulated and fabricated. The measured data shows very good agreement with the simulated one, and is presented.