Scattering of a plane electromagnetic wave by the discontinuity of impedance planes
Аннотация
Abstract A method often used for analyzing the problem of scattering by a lossy dielectric slab is an approximate one in which the dielectric slab is replaced with an impedance plane with an infinitesimal thickness. We analyzed rigorously the problem of scattering from the discontinuity between two dielectric slabs by means of the Wiener‐Hopf method. The numerical calculations in such a method is quite complicated. If this problem can be replaced with that of two impedance planes, the analysis and computation can be simplified significantly. In this paper, the scattered field of the E wave by the discontinuity of two impedance planes is analyzed by the Wiener‐Hopf technique. The results are compared with the rigorous solution of the scattered E wave by the discontinuity of two dielectric slabs. From the numerical results of the two problems, it is found that the scattering patterns agree well if the slabs are lossy (σ/ω ⩾ 1.0) and the thickness is more than the skin depth. It is also found that the magnitude of the scattered wave almost agrees if the thickness is about one wavelength. Hence, if the slab thickness is more than a certain value for the E wave with the electric field component normal to the incident plane, the impedance plane approximation is effective for the lossy dielectric slab problem.