A UTD Analysis of CSB Diffraction by a Slit in a PEC Plane

The high-frequency diffraction of a two-dimensional Complex-Source Beam (CSB) by a slit in a perfectly conducting (PEC) plane is analyzed in this paper. The approach follows a typical ray procedure in the framework of the Uniform Geometrical Theory of Diffraction (UTD). In particular, the classical UTD diffraction coefficients are analytically continued into complex space to account for the coefficient parameters to become complex in the case of evanescent wave illumination (L. Klinkenbusch and G. Manara, “Diffraction of a Complex-Source Beam by a PEC Wedge: Energy Flows of Exact and Asymptotic Solutions,” 2022 URSI Atlantic / Asia-Pacific Radio Science Conference – AT-AP RASC 2022, May 29 – June 3, 2022). Both TE (hard) and TM (soft) cases are considered. It is worth observing that the CSB illuminating the slit is uniform. This allows us to achieve a complete versatility with respect to the characteristics of the incident beam, being actually able to consider both the cases in which the impinging beam is either converging or diverging, including that one in which the beam waist is located exactly at the edge.