A Hybrid Method Based on Implicit and Explicit FDTD for Solving Transmission Line Network

This paper proposes a hybrid simulation method of the transmission line network based on the alternating direction implicit time domain finite difference (ADI-FDTD) and time domain finite difference (FDTD) methods. This method combines ADI-FDTD, FDTD, transmission line equation, Kirchhoff's law, and two-port equivalent circuit model to realize the transient responses of a transmission line network. This hybrid method is carried out by dividing into two parts that one is ADI-FDTD for small structure and the other is FDTD for large structure of the transmission line network. With the unconditional stability, the ADI-solver can use the same time step with the FDTD solver even with different space cell sizes. Further, the voltage and current responses at the terminal of a transmission line network are calculated by using the hybrid FDTD method. The simulation results are in good agreement with the HSPICE method, which verifies the accuracy of the proposed method. This method can reduce the number of simulation iterations and improve the simulation efficiency without sacrificing accuracy.