Higher-Order Diffraction of a Conducting Strip by Sommerfeld'S Solutions.

摘要

Two basic assumptions involved in applying diffraction theory to a conducting strip (or an infinite slit, by Babinet's principle) are studied. The first-order diffraction patterns and echo widths are formulated by Sommerfeld's asymptotic solutions. The effects of virtual sources induced at both edges of the strip are examined. Higher-order diffraction techniques are formulated by Sommerfeld's exact solutions in conjunction with the reciprocity theorem. Complete diffraction patterns anc echo widths of a strip of different width, under general incidence of a homogeneous plane wave, are presented and compared with the results of the first-order diffraction. The exact solution by Mathieu functions is compared with the results of complete backscattered field per unit width. The limits of the assumption that diffraction phenomena are localized have been examined by the results obtained in the present analysis. The basic concepts and techniques employed here are compared with those used earlier on the complementary problems (of a slit) by other investigators. (Author)