Diffraction of the TE10 Mode by a Symmetrical H-Step Discontinuity in a Rectangular Waveguide

The diffraction of the TE10 mode by a symmetrical H-step discontinuity in a rectangular waveguide for the multimode case is analyzed. The Wiener-Hopf technique is employed to obtain the scattering matrix. The solution for the amplitudes of the resulting modes is the sum of two parts. The first is expressed directly in terms of the parameters of the problem. The second part, which is a function of unknown coefficients that should be derived from a system of equations, represents a correction factor to the first part of the solution. Asymptotic expressions for small step discontinuities are also derived. The solutions are numerically more efficient than those obtained with matrix inversion.