Microwave bandpass and bandstop waveguide filters using printed-circuit discontinuities

This paper presents a novel method for microwave waveguide filter design. The method assumes development of novel resonators, which can be used for the higher-order waveguide filter design. Multiple resonant frequencies can be obtained using single resonating insert. Bandpass and bandstop waveguide filters, with a single or multiple frequency bands, are developed using E-plane or H-plane printed-circuit discontinuities acting as resonating elements. They are intended to operate in the X frequency band and standard rectangular waveguide (WR-90) is used for their implementation. A solution for the compact filter design is also proposed. The application of the novel method is exemplified by various bandpass and bandstop filter models, their equivalent microwave circuit representations and laboratory prototypes. Experimental verification shows good agreement between simulation and measurement results.