Diffraction by a terminated semi-infinite parallel-plate waveguide with three-layer material loading

The plane wave diffraction by a terminated semi-infinite parallel-plate waveguide with three-layer material loading is rigorously analyzed for E polarization using the Wiener-Hopf technique. Introducing the Fourier transform for the scattered field and applying boundary conditions in the transform domain, the problem is formulated in terms of the simultaneous Wiener-Hopf equations, which are solved via the factorization and decomposition procedure. The scattered field is evaluated by taking the inverse Fourier transform and applying the saddle point method. Representative numerical examples of the radar cross section (RCS) are given for various physical parameters and the backscattering characteristics are discussed in detail. Some comparisons with a high-frequency technique are also given to validate the present method.