Waveguide bandpass filter on complex resonance diaphragms

Results of electrodynamic analysis of single resonance diaphragms in the form of a rectangle window with two L-shaped combs in a rectangle waveguide and results of synthesis of bandpass filters on their basis are presented. The electromagnetic fields and critical wavenumbers of a rectangle wavegide with two L-shaped combs that form the aperture of the diaphragms are determined by the partial domain method with allowance for the field singularity on the edge. The proposed diaphragm aperture allows one not only to obtain resonator Q-factors that are higher than those of usual rectangle windows but also to obtain record low attenuation levels for this type of filters in the stop band owing to the presence of an antiresonance in the aperture’s transient characteristic.