| This dissertation deals with the formulation of a vector finite element method for the analysis of microwave circuits, electronic packages and ferrite-tuned cavity-backed slot antennas. A generalized eigenvalue problem is first formulated to examine the dispersive propagation characteristics of two-dimensional anisotropic and lossy microwave structures. Quantities such as the propagation constant, attenuation constant, characteristic impedance and field distribution of metallic traces on single and multiple substrates are evaluated. Information obtained from the solution of the eigenvalue problem is subsequently used for the analysis of complex planar microwave circuits and electronic packages. The resulting S-parameters are used to evaluate the electrical performance of the structure. At microwave frequencies, parasitic effects due to packaging, wire bonding and poor grounding may significantly alter the respective S-parameters of the original circuit.; The finite element method is then hybridized with a mixed spectral/spatial domain method of moments and diffraction theory to calculate scattering and radiation characteristics of cavity-backed slots mounted on infinite and finite ground planes with a possible dielectric or magnetic overlay. The cavity may also be filled with magnetized ferrites, thus providing tuning capabilities through altering the externally bias field. Predictions of the radiation characteristics of ferrite-tuned antennas are compared with measurements performed in the anechoic chamber. Finally, the finite element method is used to simulate wave propagation through a perfectly matched layer placed at the boundary of the computational domain to absorb propagating waves in the outward direction. The effectiveness, efficiency and accuracy of this truncation technique is thoroughly investigated through numerical simulations. |
