An Efficient Bidirectional Moving Window Finite-Difference Time Domain Method

The moving window finite-difference time domain (MW-FDTD) method reduces the computational domain by following the propagation of the main pulse front and is widely used for solving electromagnetic wave propagation problems in elongated spaces. However, when the problem space contains targets with strong reflective characteristics and the effective reflection paths exceed the coverage range of the moving window, the conventional method is prone to missing the reflected waves due to the movement of the window. Moreover, expanding the window size would affect the overall computational efficiency. To address this issue, a bidirectional MW-FDTD method is proposed, where a backward-moving window can be generated to track and calculate the reflected waves by monitoring the energy distribution within the moving window. Simulation results show that the proposed method can ensure computational accuracy while maintaining computational efficiency compared to the conventional method.