Sampling Frequency Conversion of the Time-Domain Discrete Green's Function for FDTD Diakoptics

The Finite-Difference Time-Domain (FDTD) method is one of the widely used general purpose electromagnetic field simulation methods. The rounding (quantization) error that occurs when approximating the analyzed structure with a finite difference grid can be reduced by reducing the grid spacing, but the analysis becomes large-scale and enormous computer resources are indispensable. The concept of diakoptics has been applied to the analysis of large-scale systems to mitigate the required computational resources. Authors have proposed applying diakoptics to the FDTD method by formulating the time domain discrete Green's function as a means of modeling the divided regions. In this paper, we demonstrate the improvement of the analysis efficiency by thinning out the discrete Green's function based on the sampling theorem before synthesizing a whole structure.