ИСТИНА

The report considers a problem of diffraction of a plane electromagnetic wave on a periodic layer. The layer is bounded by two surfaces. The layer's permittivity is given by a periodic function. The result of diffraction is calculated by the means of Galerkin type method proposed by Ilinskiy A.S. The method allows to reduce the initial diffraction problem to a system of first order differential equations. The layer's irregularities are of the same spatial size as the wavelength of the radiation. The inverse problem of reconstruction of the layer's inner structure can be considered in the scope of the model. For example, a 2-dimensional problem of scattering on a cylinder buried underneath a sinusoidal surface was examined earlier. The current report considers the 3-dimensional case, i.e. the layer's surface and permittivity distribution are given by arbitrary functions, that are periodic by two dimensions. The plane electromagnetic wave may have arbitrary polarization and may come from any direction. The developed computer program is verified by solving some examples allowing analytical solution.