Uniform Theory of Diffraction (UTD) Scattering from Structures, Including Higher Order Terms. Volume II. Edge Wave Edge and Vertex Diffraction.

摘要

The diffraction of an edge wave by the vertex and the edges of a semi-infinite wedge (a trihedron) is studied. The edge wave is produced by an infinitesimal electric dipole source located in close vicinity of one of the edges of the trihedron and sufficiently far from the vertex. The radiation integral of the currents that would flow over an infinite wedge, which is then truncated, is evaluated asymptotically, yielding an endpoint effect. The final result is improved by introducing a fringe current component induced by the terminating edges, and exhibits fairly good agreement with moment method computations and measured data. The field diffracted by a corner and propagating along the edge of a flat plate structure can be obtained via reciprocity. The edge wave corner diffraction coefficient thus derived may be utilized for the calculation of corner-to-corner and corner-to-edge diffraction mechanisms.