Improvements to parameter extraction techniques for FDTD simulations of handset antennas

Improved techniques for the extraction of return loss and antenna efficiency from FDTD simulations of hand-held transceivers have been proposed. The key point for both techniques resides in using a new scheme of antenna excitation via a 3D model of a thin TEM line, terminated with a template source. This permits one to extract the return loss within the line by the differential method previously developed and well tested for S-parameter analysis in microwave circuits, and now enhanced with TEM template filtering. Another advantage of applying the template source is that it provides accurate control of power delivered to the antenna. The radiation efficiency can then be calculated directly, without the need to integrate dissipated power over the whole computational domain. Depending on the problem complexity, this reduces the computing time by up to a factor of two, and at the same time ensures the 0.8 % accuracy even for the discretization of 10 cells per wavelength.