Analysis of Electromagnetic Wave Diffraction By a Semi-Infinite Strip Grating and Evaluation of End-Effects - Abstract

Abstract

Diffraction of electromagnetic wave by a semi-infinite strip grating is analyzed and end-effects contribution is investigated. In the formulation, the current induced on each strip is divided into periodic current on an infinite strip grating and the correction current induced by the truncation of the periodic structure. These currents are determined by solving a set of integral equations under the assumption that each strip is narrow relative to the wavelength. Far field representation obtained by the asymptotic evaluation of the radiation integral indicates that the scattered field by the semi-infinite grating is expressed as a sum of the Floquet's modes and the cylindrical wave diffracted at the edge of the semi-infinite grating. In order to evaluate the end-effect contributions, numerical computations are carried out for current distribution, diffraction patterns, and radiated powers by the induced correction currents.