Effect of Symmetrically-Asymmetric Arrangement of Resonant Membranes on the Frequency Characteristics of Three-Section Filters on Waveguide-Slot Membranes

Abstract

The paper presents the results of experimental measurements and numerical modeling of the amplitude-frequency characteristics (AFC) of four three-stage band-pass filters containing two resonant waveguide-slotted membranes (WSM) with a waveguide spacer between them. WSM have a complex topological structure. The filters are distinguished by a symmetrically asymmetric arrangement of the resonant WSM relative to each other. It was found that the alternation of the symmetric asymmetrical arrangement of the WSM with each other allows one to significantly change the frequency response of the filters. In particular, with an asymmetrical arrangement of the WSM between each other, the filter bandwidth is substantially less than with a symmetrical arrangement, and the attenuation values introduced by the filter beyond the passband are significantly larger. The cross-section of the waveguide was 35×15 mm, and the frequency range of the filters was from 5.5 GHz to 8.5 GHz.