Simulation of electromagnetic radiation and scattering using hybrid higher order FETD-FDTD method

The stable hybrid finite element time domain - finite difference time domain (FETD-FDTD) method is extended by incorporating higher order hierarchical basis functions in the finite element region. The use of unstructured tetrahedral elements in the modeling of antenna structure enables the application of the hybrid method to accurately model geometrically complex radiators. Pyramidal elements are used in the transition from unstructured tetrahedral elements to structured hexahedral elements of the FDTD grid. The finite element formulation incorporates the excitation of antennas using coaxial line or stripline feed with transverse electromagnetic mode (TEM). Traditional FDTD method with anisotropic perfectly matched layer (PML) is used to simulate unbounded media. The technique is extended for scattering problems, enabling the modeling and simulation of reception by antennas. Application of this method in the modeling of typical wideband antennas along with the numerical results is presented.