FDTD evaluation of scattering by metallic objects in GTEM cells

The finite difference time domain (FDTD) technique, developed in a polar coordinate system, is used to analyse the scattering by metallic objects in a gigahertz transverse electromagnetic (GTEM) cell. The advantage of using the FDTD method is the noticeable mathematical simplification, with respect to the analytical approach, which allows one to treat general structures and electrical characteristics without further analytical effort, and use of computer resources. The analysis has been carried out both at discrete frequencies, to compare our results with those in the literature, and with pulse sources to extract, by means of a discrete Fourier transform, the frequency domain behaviour of the system. The measurements inside the GTEM cell show a good correlation with those made in anechoic chambers