Explicit and Unconditionally Stable FDTD Method for Electromagnetic Problem Analysis

摘要

The Finite-Difference Time-Domain (FDTD) method has an important role in computational electromagnetics due to its advantages of simplicity, high efficiency, and parallelism. However, the traditional FDTD method must satisfy the CFL condition to guarantee the stability of the solution. Because of the limitation of CFL conditions, when the traditional FDTD method deals with electromagnetic problems with multi-scale structures, the time step size must be selected based on the smallest spatial grid size, and the calculation is inefficient. In this paper, an unconditionally stable FDTD method is introduced. This method takes a rectangular patch as the basic unit of space and eliminates the spatially unstable module as its basic idea. It not only retains the advantages of the traditional FDTD method's explicit iteration, but also overcomes the shortcomings associated with the time step and space step of traditional FDTD method, this method has explicit unconditional stability characteristics.