Two-dimensional scattering from cavity-backed aperture with resonant loading

The problem of scattering from the slit cylinders with arbitrary cross-sections located both inside and outside of each other, excluding the cases of the crossing of their surfaces, is solved by the method of analytical regularization. The method is based on the generalized Riemann-Hilbert problem technique. The particular case of the axially slotted circular cylinder with another slotted cylinder inside the cavity is considered in detail. It was shown that resonant loading causes low-frequency resonance splitting and the appearance of high-Q resonance in the longwave region. The phenomena of the "interaction" between modes in the vicinity of Morse critical points of the dispersion equation are considered. The sharp transformation of the scattering resonances and the far field patterns caused by modes "interaction" are analyzed. A variety of current, field, and cross-section results are presented.<>