Novel implementation of dual-band bandstop waveguide filter using quarter-wave resonators

Abstract

Novel implementation of microwave waveguide filter with two rejection bands is presented in this paper. Quarter-wave resonators are implemented in planar technology, and in the research, they are used as resonant septa inserted in the waveguide. Resonators with single resonant frequency are considered, as well as their equivalent circuits. The observed resonator responses are analyzed in details, in order to design second-order filter with a single rejection band. Mutual coupling between the resonators on the same printed-circuit insert is investigated. The second-order filter with two stopbands is implemented using observed resonators and the proposed method for filter design. The proposed method for filter design opens possibility for realization of higher order filters with multi-stopbands.

Keywords

• Quarter-wave resonator
• bandstop filter
• dual-band bandstop filter
• resonant insert
• waveguide technology