Application of the discrete Fourier transform method to thin dielectric structures [EM scattering]

The discrete Fourier transform method is a numerical technique designed to take advantage of the convolution structure that often appears in the differential-integral equations arising from electromagnetic scattering. It used the fast Fourier transform (FFT) to compute both the derivatives and the convolution integrals. As a consequence, this method is easy to program, uses less computer memory than comparable methods, yields accurate predictions, and in general, offers a better rate of convergence. This technique, which is particularly suited for solving problems where the scatterer is made of a dielectric material and has a shape which can be approximated accurately by a rectangular grid, is applied to thin dielectric slabs with both electric and magnetic properties. It is shown that by choosing the conductivity sufficiently large, a thin dielectric slab behaves like a metallic plate. On the other hand, with a suitable choice of conductivity, a particular thin dielectric slab will act like a resistive plate