A Huygens' Principle Based Ray Tracing Method for Diffraction Calculation

Abstract

In conventional ray tracing methods, diffraction calculations for wedges are typically based on the uniform theory of diffraction (UTD). However, UTD is both inaccurate and computationally expensive in the calculation of multiple diffractions. In order to mitigate these shortcomings, a Huygens' principle based method is proposed as an alternative or extension to the conventional UTD. This method captures rays on properly chosen Huygens' surfaces and creates equivalent emitters for subsequent secondary ray launches based on the captured rays. Despite the extra effort of creating a Huygens' surface, compared with UTD, this method has considerably improved flexibility in handling complex geometrical shapes and it preserves the accuracy over multiple diffractions. Furthermore, by properly choosing the Huygens' surface and equivalent emitters, both computational complexity and accuracy can be controlled.