UTD Shooting-and-Bouncing Extension to a PO/PTD Ray Tracing Algorithm

Abstract

This paper deals with the efficient combination of three well-established electromagnetic modeling methods, a Shooting-and-Bouncing-Rays (SBR) algorithm on the basis of the Geometrical Optics (GO), a source-based calculation of scattered field strengths using Physical Optics (PO) and Physical Theory of Diffraction (PTD), and diffraction calculation on the basis of the Uniform Theory of Diffraction (UTD). While the conventional GO-PO/PTD methods are able to accurately calculate wedge contributions to scattered fields, the further propagation of diffracted rays is generally not considered in SBR approaches. Thus, the aim of this paper is to describe the implementation of diffracted rays according to the UTD concept into an SBR code. This novel implementation allows for the modeling of double diffraction and reflected-diffractedreflected paths in complex scenarios consisting of a very large number of surface elements as well as the accurate simulation of cavities. The comparison with numerically exact reference simulations proves that the proposed hybrid GO/UTD-PO/PTD algorithm yields excellent results and that the UTD-SBR extension definitely improves the simulations of the ray tracing algorithm also for realistic objects.