Improvements to diffraction coefficient for non-perfectly conducting wedges

Holm proposed a heuristic uniform theory of diffraction coefficient for nonperfectly conducting wedges as an extension to the heuristic one given by Luebbers. This work improves limitations of Holm's diffraction coefficient in the illumination region, where it is not accurate. The accuracy of the improved diffraction coefficient is very close to that of Maliuzhinets' solution. The improvements are valid for parallel and perpendicular polarizations.