| Time-domain finite-element method (TDFEM) is studied for electromagnetic analysis. Solutions to a series of open problems that impede the popularity of the TDFEM are presented. These problems include the development of accurate and efficient absorbing boundary conditions for the mesh truncation of the TDFEM, the complete elimination of matrix solution required by the TDFEM solution of vector wave equations, the higher-order TDFEM schemes, the TDFEM modeling of general dispersive media, and the general stability analysis of the TDFEM. First, fast two-dimensional and three-dimensional time-domain finite element-boundary integral methods are developed for analyzing open-region electromagnetic transient scattering. Second, a higher-order TDFEM scheme is presented to enhance the accuracy and efficiency of the zeroth-0order TDFEM schemes. Third, a set of three-dimensional orthogonal vector basis functions is developed to eliminate the matrix solution required at each time step. Fourth, a general formulation is described for the TDFEM modeling of electromagnetic fields in a general dispersive medium. Fifth, both two-dimensional and three-dimensional perfectly matched layer (PML) schemes are developed for TDFEM simulation of open-region electromagnetic scattering and radiation problems. Sixth, a general approach is proposed for the stability analysis of the TDFEM. Finally, the great application potential of the proposed advanced TDFEMs is demonstrated by their application to the simulation of microstrip patch antennas. |
