On the numerical errors in the 2D FE/FDTD algorithm for different hybridization schemes

Numerical experiments are carried out to study the accuracy of the two-dimensional Finite-Element/Finite-Difference Time-Domain (FE/FDTD) hybrid algorithm with three different hybridization schemes. The physical space is split into two domains viz., the finite difference (FD) and finite element (FE) domains. In the FD domain, a uniform Cartesian grid is used and in the FE domain, triangular elements with edge vector basis functions are used. Newmark-β scheme is used for temporal discretization in the FE domain. The unphysical reflections introduced by the FE domain for the different schemes are compared by computing the 2-D radar cross section of the FE domain surrounded by the FD domain. Computed results of scattering by a PEC circular cylinder for TE_z incidence using the three schemes and the traditional FDTD algorithm are presented.