Reflection resonances and natural oscillations of two-aperture iris in rectangular waveguide

The total reflection resonances that take place at the excitation of a two-slot resonant iris in rectangular waveguide are discussed in this paper. Considering the iris as an open-resonator-waveguide structure, the pair of natural oscillations responsible for such resonances was numerically found and investigated. It is pointed out to a parallel between the rejection resonances in two-slot irises and "locked"-mode resonances in multimode waveguide structures.