Analysis of diffraction by material discontinuities in thin material-coated planar surfaces based on Maliuzhinets method

The electromagnetic diffraction of a plane wave (transverse electric case) by a two-part material coated perfectly conducting ground plane and a material-coated perfectly conducting half plane is studied using the Maliuzhinets method. Each of the coatings is assumed to be electrically thin so that it can be replaced in the analysis by a generalized impedance boundary condition of 0(t) where t is the corresponding coating thickness. To solve each of the boundary value problems completely, one needs to impose an additional constraint which is determined here by matching an approximate quasi-static solution with the corresponding Maliuzhinets solution in the common region of overlap. This requires the asymptotic evaluation of the Maliuzhinets functions in various regions of the spectral domain. Furthermore, several constants that appear in the analysis are exactly related to the field and its derivatives evaluated at the edge or junction of the body under study. The backscattered and bistatic echo widths of a partially coated perfectly conducting half plane are computed with the solutions developed here (including multiple interaction) and compared with an independent moment method solution. The agreement between the two solutions is excellent.