First-Order Diffraction at Strips and Polygonal Cylinders

General asymptotic expressions have been derived for first-order edge-diffracted waves generated by both uniform and nonuniform components of the surface sources. In this chapter this general theory is applied to high-frequency diffraction at strips and cylinders with triangular cross-sections. These specific diffraction problems have been studied comprehensively and reported in the literature. In particular, the uniform asymptotic expressions for the directivity pattern and for the surface field at the strips have been derived by Ufimtsev. High-frequency diffraction at polygonal cylinders was investigated by Morse and Borovikov. The chapter considers the problems to demonstrate the first applications of physical theory of diffraction (PTD). The physical optics (PO) part of a scattered field generated by the uniform components of the surface sources is determined by the integrals. The chapter presents the numerical analysis of a scattered field by utilizing different approaches.