ABSTRACT
All of the applications and examples given in earlier chapters have involved only the electromagnetic fields within or adjacent to the scattering or radiating object such that the fields are contained within the FDTD calculation space. FDTD can also be applied to analyze scattering from radar targets or radiation from antennas, with the desired results being the far zone scattered or radiated fields that lie outside the FDTD space. Near zone to far zone transformations applicable to time harmonic fields are well known. Early FDTD calculations of far zone scattered fields used these frequency domain transformations. 1 Because of this the FDTD far zone results were obtained at only one frequency per FDTD calculation run, and usually obtained with sinusoidal time variation excitation. 2
