Efficient FDTD analysis of antenna-channel interaction via macromodeling

The use of the finite-difference time-domain (FDTD) method for wireless channel modeling has gained significant popularity due to its simple implementation and its ability to extract wideband responses from a single simulation run. FDTD based techniques, despite providing accurate channel characterizations, have often employed point sources in their studies, mainly due to the difficulty in modeling fine geometrical details or features inherent in antennas into a discrete spatial domain. The underlying influences of the antenna on wave propagation and in the case of multiple antenna systems, the issue of mutual coupling between the antenna elements have thus been disregarded. With the growing interest in small antenna-based MIMO communication systems, this paper presents a possible approach for the efficient space-time analysis of such systems in wireless channels. Specifically, a suitable technique for representing antennas in terms of their FDTD-compatible macromodels and their subsequent incorporation into realistic channel models is proposed. This work is an extension which deals with a reciprocity-based approach for macromodeling minimum scattering antennas.