Title :
High-frequency scattering from a wedge with impedance faces illuminated by a line source. II. Surface waves
Author :
Manara, Giuliano ; Tiberio, Roberto ; Pelosi, Giuseppe ; Pathak, Prabhakar H.
Author_Institution :
Dept. of Inf. Eng., Pisa Univ., Italy
fDate :
7/1/1993 12:00:00 AM
Abstract :
For pt.I see ibid., vol.37, no.2, p.212-18 (1989). In Part I a rigorous integral representation for the field scattered at a finite distance from the edge of an impedance wedge when it is illuminated by a line source was derived. It was shown that the total field can be expressed as the sum of the geometrical optics (GO) field, the field diffracted by the edge, and terms related to the excitation of surface waves. The double spectral integral representation for the diffracted field was asymptotically evaluated there, in the case in which no surface wave can be supported by the two faces of the wedge. In particular, the high-frequency solution was expressed in the special format of the uniform geometrical theory of diffraction (UTD). Here, field contributions related to the surface wave excitation mechanism are examined. By a convenient asymptotic approximation of the integrals, a high-frequency solution which is uniform with respect to aspects of both incidence and observation is obtained. Moreover, this solution has useful symmetry properties so that it explicitly exhibits reciprocity. Numerical results are presented to show the relevance of the surface wave terms in the evaluation of the field
Keywords :
electromagnetic wave scattering; geometrical optics; integral equations; numerical analysis; HF scattering; asymptotic approximation; electromagnetic scattering; geometrical optics; high-frequency solution; impedance wedge; integral representation; line source illumination; numerical results; surface wave excitation; uniform geometrical theory of diffraction; Conductors; Electromagnetic scattering; Geometrical optics; Integral equations; Optical diffraction; Optical scattering; Optical surface waves; Physical theory of diffraction; Surface impedance; Surface waves;
Journal_Title :
Antennas and Propagation, IEEE Transactions on