Hybridization of the FDTD method with use of the discrete Green´s function

In this contribution, a hybrid technique is presented which combines the finite-difference time-domain (FDTD) method and the discrete Green´s function (DGF) formulation of this method. FDTD is a powerful technique for the analysis of complex penetrable objects but its application is not efficient when the computational domain includes many free-space cells. Therefore, the hybrid method was developed which is applicable to complex geometries comprising a wire antenna mutually coupled with an inhomogeneous dielectric scatterer. In the developed method, the antenna and the scatterer are separated using the surface equivalence theorem. Then, the dielectric domain is simulated using the FDTD method whilst the wire antenna is simulated using the DGF formulation of FDTD. Obtained results demonstrate that both methods can be perfectly coupled without introducing any additional errors to the FDTD solution (assuming infinite numerical precision of computations).