| The solution of electromagnetic scattering by objects located in planar, multilayered media has long been the subject of active research. For layered-media integral equation solutions via the Method of Moments (MoM), the O({dollar}Nsp2{dollar}) matrix fill is often prohibitively expensive, even for problems of moderate size. For spatial-domain formulations, this is due to the presence of the Sommerfeld integrals required for obtaining the Green's functions in spatial form.; These integrals are completely avoided through use of the complex-image method, which represents the spatial-domain Green's functions in closed form. However, this method is not without limitations, most notably a finite region of validity and an undesirable sensitivity to the choice of requisite parameters. This thesis focuses on methods for overcoming these limitations, to allow robust implementation of the method within the framework of an automated, general-purpose analysis program, applicable to the solution of scattering from arbitrarily shaped objects residing in any number of dielectric layers. Evaluations of several possible improvements to the original complex-image method are presented. A new approach is also presented for representing the angular-dependent Green's function terms that are required when both horizontal and vertical electric currents are present.; The complex-image method is applied in this work to the MoM solution of the mixed-potential form of the electric field integral equation (MPIE). Several numerical results are presented for planar and nonplanar objects, including a microstrip patch antenna, wire dipole antennas penetrating dielectric half-spaces, and a microstrip air bridge. These results are compared with measurements or the results from other programs whenever possible.; A brief discussion of scattering parameter extraction is also covered, with a comparison of the Prony and Generalized Pencil-of-Functions (GPOF) methods. |
