Rigorous Coupled-Wave Analysis in Calculating the Electromagnetic Scattering from a Radio-Absorbing Material

摘要

The paper is related to the rigorous coupled-wave analysis (RCWA) for the calculation of the reflection of electromagnetic waves from a radio absorbing material (RAM). The goal of this study is, first, to check the applicability of the RCWA method for the calculation of the reflection indices of the materials used in modern anechoic chambers and, second, to evaluate its feasibility in subsequent applications for optimization of the characteristics of anechoic chambers. We shall consider the rigorous coupled-wave analysis, as well as some of its modifications: the ETMA method and the method of partial solution. The results of the calculations are given for a commercial wedge-shaped radio-absorbing material. The method of layered approximation is also considered. The approximate and exact solutions are shown to be in good agreement, including the most important case of incident angles near 90°.