SCATTERING OF AN ELECTROMAGNETIC PLANE WAVE FROM A PERFECTLY ELECTRICALLY CONDUCTING HALF-PLANE IN THE PROXIMITY OF PLANAR MEDIA DISCONTINUITIES

The problem of scattering of electromagnetic waves from a perfectly electrically conducting (PEC) half-plane is a classical problem in the field of electromagnetics and is the basis of the GTD (geometrical theory of diffraction). The application of this theory to modern aerospace structures is hampered due to the presence of media discontinuities which alter the scattering behavior. Therefore, the study of diffraction in the presence of such discontinuities is an important prerequisite to applying the GTD to practical problems. Two related problems are considered in this study which involve planar media discontinuities. The first configuration concerns a planar interface between two semi-infinite, homogeneous media with a PEC half-plane covering half of the interface. The second configuration concerns a dielectric slab embedded in a contrasting medium. On the upper surface of the slab resides a PEC half-plane. Both structures are assumed to be excited by a transverse magnetic plane wave.; The boundary value problems are structured as integral equations involving the electric field which is tangential to the interface. The integral equations are Fourier transformed to create Wiener-Hopf equations which are then solved. The process of factorization is performed using a formal integral factorization which is converted into a form that is amenable to numerical evaluation. The solution is structured as a radiation integral and is evaluated asymptotically to arrive at the far field ray-optic contributors.; Data is presented for the interface problem to exhibit distinctive properties of the solution. Sample cases of practical interest are given. The data is considered in the light of present theory concerning wave structure about a dielectric interface and an analysis of the significant features of the data is conducted.