Diffraction by a Slit in a Thin Material Screen

The plane wave diffraction by a slit in a material screen is analyzed using the Wiener-Hopf technique together with generalized boundary conditions (GBC). Exact and high-frequency asymptotic solutions are obtained. The scattered field is evaluated asymptotically based on the saddle point method and a far field expression is derived. Numerical examples on the far field intensity are presented and the scattering characteristics of the slit are discussed.