An Efficient ME-PML-based SC-ADI-FDTD Method for Electromagnetic Analysis of Microstrip Structures

To further relieve computation burdens and improve absorption accuracies, we develop an efficient amelioration of the complex-frequency-shifted perfectly matched layer (CFS-PML) by introducing auxiliary differential equations (ADE) and matrix exponential (ME) techniques for modeling the system-combined alternating- direction-implicit finite-difference time-domain (SC- ADI-FDTD) problems. By employing ME technique, the proposal develops into the compact first-order differential matrix form applied to avoiding convolution operations, variable replacements, and formulation rearrangements during mathematical derivations. Furthermore, the repeated calculation can be omitted and the CPU time can be saved due to adopting the SC-ADI-FDTD as compared with the original ADI-FDTD. Due to higher accuracies achieved by the proposal, therefore, it can come closer to terminate smaller physical regions with targets, leading to palpable improvements in memory and CPU time. By adopting electromagnetic applications, the proposed ME-based SC-ADI-FDTD formulations can not only achieve better absorption accuracy than the SC-ADI-FDTD, but also obtain higher efficiency than the conventional FDTD method.