A NEW THEORY FOR SCATTERING OF ELECTROMAGNETIC-WAVES FROM CONDUCTING OR DIELECTRIC ROUGH SURFACES

The problem of scattering of electromagnetic waves from a conducting o r dielectric rough surface with arbitrary shape is studied. An exact s olution, using a differential method, is provided for a plane wave wit h one-dimensional irregularity of the interface. The proposed formalis m involves using the covariant form of Maxwell equations written in no northogonal coordinate system. This permits the analytical writing of the exact boundary conditions. The problem is reduced to the resolutio n of a linear system of partial differential equations with constant c oefficients, and to the computation of eigenvalues and eigenvectors of truncated infinite matrix. Numerical application is made to show the angular distribution of energy density in the case of an arbitrary pro file of the scattering surface and its evolution when the nonperiodic profile tends to become periodic. The near field is computed on the in terface and its enhancement in the illuminated region is well observed . It increases with the height of the irregularity and with the freque ncy.