Spectral domain analysis of electromagnetic wave scattering by an infinite plane metallic grating

A new method, based on the spectral domain analysis, is presented for solving the electromagnetic wave scattering by an infinite plane metallic grating. The key point of the present method is discretization of spectral formulation in terms of the sampling theorem. Two different polarizations, transverse magnetic (TM) and transverse electric (TE) excitations, are considered here. Accuracy of the present method is examined numerically by comparison with the rigorous Wiener-Hopf solutions which are applicable only to a special case. Since the end effect of a conducting strip is taken into account analytically, final results show enough convergence to evaluate the near fields as well as the far fields with small matrix calculations. Some numerical examples are shown mainly for surface current distributions to make clear the differences between the two different polarizations.