UTD solution for electromagnetic scattering by a circular cylinder with thin lossy coatings

A uniform geometrical theory of diffraction (UTD) solution is obtained for the field exterior to a two-dimensional circular cylinder with a thin lossy dielectric coating. The solution is convenient for engineering applications due to its simple ray format. In the lit region, the geometrical optics (GO) solution consists of the direct incident ray and the reflected ray. In the shadow region, the geometrical theory of diffraction (GTD) uses the creeping-wave format to calculate the diffracted field. In the transition regions adjacent to the shadow boundaries, where the pure ray optical solution fails, a `universal´ transition integral is used for the UTD solution to calculate the field. Numerical values for the essential transition integral are deduced, by a heuristic approach, from alternative representations of the Green´s function for a circular cylinder with coating. Numerical results obtained from the UTD solution show excellent agreement with the eigenfunction results for cylinders with thin dielectric coatings