Modelling parasitically-coupled patch antennas using the finite-difference time-domain technique

With the increasing interest in the use of printed circuit techniques for the manufacture of millimetre-wave antennas, there is a need to accurately model the radiation, coupling, susceptive loading and resonance mechanisms in order to determine the antennas´ input and far-field responses. For instance, with antenna elements fabricated on a high permittivity dielectric, such as alumina, the resonant behaviour of the antenna may be strongly dependent upon the size of the dielectric owing to the level of surface wave radiation. Furthermore, printed antennas tend to be formed into arrays of elements, and therefore coupling and feed line effects must also be considered in the design procedure. The aim of the paper is to demonstrate the use of a general field solving technique in the analysis of patch antennas. In this example, the finite-difference time-domain (FDTD) technique is applied to determine the characteristics of a mutually-coupled array of narrow microstrip patches