Use of Gaussian ray basis functions in ray tracing methods for applications to high frequency wave propagation problems

Traditional ray tracing approaches require a large number of geometrical optical (GO) ray tubes, and can become inefficient in many practical applications. The pulse-type basis functions of GO ray tubes cannot provide a good representation in the field expansion if the field to be expanded is not locally planar or the size of the GO ray tubes is too large. A previously developed Gaussian ray basis function (GRBF) has a Gaussian-type amplitude distribution and is suitable to replace a GO ray tube in the ray tracing approaches because the Gaussian-type distribution tends to yield a more efficient field expansion. The GRBFs are incorporated into existing computer programs of generalised ray expansion (GRE). Numerical results validate its accuracy and efficiency in comparison with GO-based GRE for the prediction of EM scattering from open cavities