When solving the electromagnetic issues, the Finite Difference Time Domain method is proposed. It is a simple and effective solution to calculating the dispersion and radiation of the electromagnetic wave in time domain. However, it only could be used in the limited space area as the capacity of computer memory has limitation. Thus, the perfectly matched layer absorbing boundary condition is necessary to simulate the open areas electromagnetic issues. Avoiding the human error accumulation, the numerical stability conditions should also be introduced in the electromagnetic scattering simulation. When the researchers is considering the above mentioned factors, the simulation results must be get faster and also be more accurate.
This study is based on the principle of the finite difference time do-main method (FDTD), which is widely applied in the electromagnetic calculation, on the conditions of reasonable the appropriate baseband Gaussian pulse excitation source choice and also setting a Perfectly matched layer (PML) absorbing boundary conditions. Give full consideration to the numerical stability conditions, it should select the appropriate time step and space step. This paper simulates the TM wave scattering in the two-dimensional space by Matlab, bring out the electromagnetic wave scattering situation of square cylindrical.