Application of Hybrid FETD-FDTD Method in the Modeling and Analysis of Antennas

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