Scattering by right angle dielectric wedge

An asymptotic solution of electromagnetic waves scattered by a right-angled dielectric wedge for plane wave incidence is obtained. Scattered far fields are constructed by waves reflected and refracted from dielectric interfaces (geometric-optical fields) and a cylindrical wave diffracted from the edge. The asymptotic edge-diffracted field is obtained by adding a correction to the edge diffraction of physical optics approximation, where the correction field in the far-field zone is calculated by solving a dual series equation amenable to simple numerical calculation. The validity of this result is assured by two limits of relative dielectric constant epsilon of the wedge. The total asymptotic field calculated agrees with Rawlins' (1977) Neumann-series solution for small epsilon and the edge diffraction pattern is shown to approach that of a perfectly conducting wedge for large epsilon. Calculated far-field patterns are presented, and the accuracy of a physical optics approximation is discussed.