A uniform double diffraction coefficient for a pair of wedges in arbitrary configuration

• Published in: IEEE transactions on antennas and propagation Vol. 53; no. 2; pp. 702 - 710
• Main Author: Albani, M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Asymptotic diffraction theory; Closed-form solution; Diffraction, scattering, reflection; Electromagnetic coupling; Electromagnetic diffraction; electromagnetic edge diffraction; Electromagnetic scattering; Exact sciences and technology; Fresnel reflection; Optical diffraction; Optical scattering; Physical theory of diffraction; Radar scattering; Radiocommunications; Radiowave propagation; Studies; Telecommunications; Telecommunications and information theory; Testing; uniform theory of diffraction (UTD); wedges; wedges; Accuracy; electromagnetic edge diffraction; Electromagnetic wave propagation; Electromagnetic wave diffraction; Analytical method; Moment method; Shadow; Numerical simulation; uniform theory of diffraction (UTD); Integral representation; Asymptotic diffraction theory
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2004.841289

An analytic closed-form solution is presented for the double diffraction at a pair of arbitrarily placed wedges that is suitable to be used in a uniform theory of diffraction (UTD) ray description framework. Here, the particular assumption, present in all the past literature, that the two diffracting edges are coplanar is removed. The doubly diffracted (DD) field at a pair of wedges is constructed via spectral synthesis. Such a procedure provides a double spectral integral representation of the DD field that is asymptotically evaluated by resorting to transition functions, typical in double diffraction problems, that can be expressed in terms of generalized Fresnel integrals. The final expression is arranged in the typical UTD fashion and contains a uniform double diffraction dyadic coefficient. The DD field behavior is analyzed in its transition regions to show how the DD field smoothly compensates for the total field discontinuities occurring at shadow boundaries where a singly diffracted field from a wedge is shadowed by the other wedge. Numerical examples are provided to verify such analysis and to test the accuracy of our UTD ray description against method of moments full wave results.