Efficient Evaluation of Equivalent-Principle Sources in MoM-FDTD Hybrid Method by Employing Spatial Interpolation and Adaptive Sampling

MoM-FDTD hybrid approach requires the information to be exchanged forth and back between the MoM-regions and the FDTD-regions coupled through the Huygens´ surfaces. For electrically large structures, evaluation of the electric and magnetic field components and related equivalence-principle sources on the Huygens´ surfaces can represent a significant (even dominant) fraction of the total solution time required for the problem. In this paper, we demonstrate a possibility of increasing computational efficiency of the MoM-FDTD hybrid method by employing spatial interpolation combined with adaptive sampling in calculating the electric and magnetic field components and the effective sources on the Huygens´ surfaces. Numerical examples show that the proposed approach offers a considerable CPU time saving.