Phase Space Gaussian Beam Summation Analysis of Half Plane Diffraction

The canonical problem of scattering of an ultrawideband (UWB) plan wave by a perfectly conducting half plane is analyzed via the UWB frame-based Gaussian beam summation (GBS) formulation of . The scattered field is described as a sum of isodiffracting-Gaussian beams (ID-GB) that emerge from the edge in a discrete frequency-independent lattice of directions, plus beams that describe the geometrical optics reflections. Asymptotic expressions for the diffracted beams excitation amplitudes are derived, interpreted, and validated via a comparison with an exact numerical calculations. The beams that are strongly excited are those associated with the geometrical optics and the edge diffracted rays. As discussed in the conclusions to this paper, the quality of the present GBS scheme deteriorates for grazing incidence and/or observations, hence we propose an alternative GBS scheme that is expected to be more useful for edge diffraction problems. This issue will be presented in a future publication.