Ray Methods for Tapered Dielectric Antennas

Due to their simplicity and versatility ray methods are well suited to the analysis of tapered dielectric antennas wherein the availability of fast algorithms which can yield a sufficiently accurate representation of the surface field distribution on the antenna is of great importance. The accuracy of the ray optical calculations can be improved substantially without appreciably increasing complexity by modifying the ray paths with the inclusion of the lateral shifts on the boundaries. Here this modification is applied to the canonical problem presented by a two-dimensional homogeneous wedge. The interrelations between the laterally shifted ray representation and the recently developped exact integral representation for the wedge are investigated. The latter is utilized as a reference solution to reveal the analytical approximations implicit in the ray construction and to test the numerical accuracy and the ranges of validity of the ray optical calculations.