Development and applications of a hybrid finite element method (FEM)/method of moments (MoM) tool

Hybrid FEM/MoM methods combine the finite element method (FEM) and the method of moments (MoM) to model inhomogeneous unbounded problems. These two methods are coupled by enforcing field continuity on the boundary that separates the FEM and MoM regions. Based on the hybrid FEM/MoM method, EMAP5 is a numerical software package designed by the Electromagnetic Compatibility Lab of the University of Missouri-Rolla to model electromagnetic problems.; This dissertation presents the latest improvements made to the EMAP5 code. Impedance boundary conditions (IBCs) that simulate imperfect thin conducting structures, thin dielectric sheets are incorporated in the FEM part in the first paper. Properties of the new formulation are investigated and the formulation is used to model three practical electromagnetic problems. Three different models, probe model, coaxial-cable model and strip model, that can be used to represent coaxial cable feeds or vias in printed circuit board power bus structures are investigated in the second paper. A hybrid formulation applying a set of hierarchical TVFE's developed by Webb and Forghani. Coupling between higher-order FEM and MoM employing Rao-Wilton-Glisson (RWG) functions is presented in the third paper. A type of practical problems about how to model microstrip structures with a thin trace is discussed in the fourth paper.