ABSTRACT
The finite difference time domain (FDTD) method has gained tremendous popularity in the past decade as a tool for solving Maxwell’s equations. FDTD has been used very successfully in the design of antennas for several applications ranging from simple microstrip antennas to complex phased-array antennas. The empirical models are generally based on some fundamental simplifying assumptions concerning the radiation mechanism of the antenna. The assumptions are extracted from experimental experience. Phenomena such as surface wave propagation in a microstrip antenna and dispersion are generally not included in these models. FDTD is a discrete representation of Maxwell’s equations using, in its common form, a central difference scheme in both time and space. The conductor treatment in the FDTD formulation is not difficult. For many applications that require to model scattering from an object or a radiating antenna situated in free space, it is desired that the scattered or radiated fields propagate into boundless space.
