Characteristic analysis for FDTD based on frequency response

A characteristic analysis method for finite difference time domain (FDTD) based on frequency response is presented. By this method, the characteristic of FDTD can be mapped into the characteristic of frequency response of a system. So FDTD can be studied through the system. In this paper, we deduce the frequency response of the system with respect to one dimensional scalar wave in free space, discuss the distortion of magnitude and phase, build the relation between frequency and attenuation and phase velocity, then reveal the effect of FDTD algorithm on signal and give the criterion to choose appropriate signal for simulation to avoid excessive distortion. At last, the simulation validates the theory analysis.