An incremental theory of diffraction: electromagnetic formulation

A scalar formulation of the incremental theory of diffraction (ITD) has been introduced by Tiberio and Maci (see ibid., vol.42, no.5, 1994), which provides a self-consistent, high-frequency description of a wide class of scattering phenomena, within a unified framework. In this paper, this method is extended to electromagnetic problems. The total field is represented as the sum of a generalized geometrical optics field plus incremental diffracted field contributions. Explicit dyadic expressions of incremental diffraction coefficients are derived for wedge-shaped configurations. The formulation of the field is uniformly valid at any incidence and observation aspects, including caustics and shadow boundaries of the corresponding ray field description. Numerical results are presented and compared with those obtained from different techniques.>