多时间步长时域有限差分法分析微波电路

Analysis of Microwave Circuits Using Multi-Time-Step Finite-Difference Time-Domain Method

提出在非均匀网格空间的粗网格区域采用大时间步长,细网格区域采用小时间步长的多时间步长时域有限差分(MTS -FDTD)法,并对其稳定性条件进行了分析。该方法通过应用多个时间步长替代传统非均匀时域有限差分(NU- FDTD)法的单一时间步长的算法来提高计算速度。通过应用MTS- FDTD方法模拟自由空间中给定激励下某点的场和微带低通滤波电路。数值结果表明,与传统NU- FDTD法相比,MTS- FDTD法在保持同等计算精度的条件下计算速度提高了46%以上。

An multi-time-step finite-difference time-domain （MTS-FDTD） method which uses long time step in coarse domain and short one in fine domain is presented, and the stability condition of the method is analyzed in this paper. The algorithm uses multi-time steps to replace single time step in traditional non-uniform finite-difference time-domain （NU-FDTD） method to enhance the computing speed. The MTS-FDTD method is used to simulate fields at one point in free space by given source and microstrip low-pass filter circuit. Numerical results show the MTS-FDTD method increases computing speed over 46% than traditional NU-FDTD method with same numerical precision.