A uniform GTD formulation for the diffraction by a wedge with impedance faces

A uniform high-frequency solution is presented for the diffraction by a wedge with impedance faces illuminated by a plane wave perpendicularly incident on its edge. Arbitrary uniform isotropic impedance boundary conditions may be imposed on the faces of the wedge, and both the transverse electric (TE) and transverse magnetic (TM) cases are considered. This solution is formulated in terms of a diffraction coefficient which has the same structure as that of the uniform geometrical theory of diffraction (UTD) for a perfectly conducting wedge. Its extension to the present case is achieved by introducing suitable multiplying factors, which have been derived from an asymptotic evaluation of the exact solution given by Maliuzhinets. When the field point is located on the surface near the edge, a more accurate asymptotic evaluation is employed to obtain a high-frequency expression for the diffracted field, which is suitable for several specific applications. The formulation described in this paper may provide a useful, rigorous basis to search for a more numerically efficient but yet accurate approximation.

[1]  J. Bowman.  HIGH-FREQUENCY BACKSCATTERING FROM AN ABSORBING INFINITE STRIP WITH ARBITRARY FACE IMPEDANCES , 1967 .

[2]  R. Kouyoumjian,et al.  Surface wave diffraction by a truncated dielectric slab recessed in a perfectly conducting surface , 1979 .

[3]  Thomas B. A. Senior,et al.  Backscattering from resistive strips , 1979 .

[4]  Giuliano Manara,et al.  Scattering by a strip with two face impedances at edge‐on incidence , 1982 .

[5]  R. Tiberio,et al.  Calculation of the high-frequency diffraction by two nearby edges illuminated at grazing incidence , 1984 .

[6]  V. Vaccaro.  Electromagnetic Diffraction from a Right-angled Wedge with Soft Conditions on One Face , 1981 .

[7]  R. Kouyoumjian,et al.  A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface , 1974 .

[8]  W. Burnside,et al.  High frequency scattering by a thin lossless dielectric slab , 1983 .

[9]  G. D. Maliuzhinets.  Excitation, Reflection and Emission of Surface Waves from a Wedge with Given Face Impedances , 1958 .

[10]  J. Keller,et al.  Geometrical theory of diffraction. , 1962, Journal of the Optical Society of America.

[11]  Giuseppe Pelosi,et al.  High-frequency scattering from the edges of impedance discontinuities on a flat plane , 1983 .

[12]  R. Tiberio,et al.  An analysis of diffraction at edges illuminated by transition region fields , 1982 .

[13]  T. Senior.  Diffraction Tensors for Imperfectly Conducting Edges. , 1975 .

[14]  T. Senior.  Scattering by resistive strips , 1979 .

[15]  G. Franceschetti,et al.  Rim loaded reflector antennas , 1980 .

[16]  P. Christiansen.  Comparison between edge diffraction processes , 1974 .

[17]  R. Tiberio,et al.  A uniform GTD solution for the diffraction by strips illuminated at grazing incidence , 1979 .

[18]  G. Franceschetti,et al.  Electromagnetic scattering by a half plane with two face impedances , 1976 .