Scattering by open metal obstacles in a circular waveguide: dyadic Green's function approach

The problem of scattering from an arbitrarily shaped discontinuity in a circular waveguide is presented. The method of analysis is based on the method of moments (MoM) discretization with the electric dyadic Green's function obtained for a circular waveguide. In this formulation, the Green's dyadic is derived for an arbitrarily oriented electric dipole in the eigenmode expansion form normalized to unity power. Examples of scattering by a thin radial strip and an annular ring are considered, and the results of the scattering parameters are compared with those obtained using a finite-difference time-domain (FDTD) commercial software.