| In this dissertation, accurate and efficient numerical techniques are developed for the computation of the input impedance and the near-zone electric field distribution for printed strip dipole antennas in layered media. Spectral domain techniques are used in conjunction with Galerkin's method (with piecewise-sinusoidal and triangular basis functions) to obtain the current distribution on the antenna. The resulting two-dimensional Sommerfeld integrals are efficiently computed by expressing the angular integral as a finite number of incomplete Lipschitz-Hankel integrals, which in turn are calculated using series expansions. A numerical integration routine is used for the outer integral.; The computational efficiency for the elements in the impedance matrix is further improved by using the expansion in terms of incomplete Lipschitz-Hankel integrals to develop a novel asymptotic extraction technique. When compared with another asymptotic extraction technique from the literature, this technique is found to have a number of advantages.; The usefulness of these techniques is demonstrated by applying them to the analysis of a hyperthermia applicator, and other problems involving printed strip dipole antennas. The techniques which are developed in this dissertation are very general, and can also be applied to the analysis of a large number of different planar structures. |
