Solution of problems of diffraction by planar resonant obstacles in a rectangular waveguide, with allowance for edge singularities in the behavior of the field

The paper examines the diffraction of Hpq or Epq modes at the junction of two rectangular waveguides which includes a thin resonant diaphragm. Edge singularities of the field's behavior at the junction are taken into account, and a compact algorithm for solving the diffraction problem is developed, which assures rapid convergence of the approximate results. The junctions of rectangular waveguides, one of which can be beyond cutoff, are analyzed numerically for a wide range of parameter values.