PML Implementation in a Nonconforming Mixed-Element DGTD Method for Periodic Structure Analysis
PML Implementation in a Nonconforming Mixed-Element DGTD Method for Periodic Structure Analysis
复制标题
DOI：
10.1109/tap.2019.2927663
复制
发表时间：
2019-07
影响因子：
5.7
通讯作者：
H. Bao;L. Kang;S. Campbell;D. Werner
中科院分区：
文献类型：
--
作者：
H. Bao;L. Kang;S. Campbell;D. Werner
提出了一种带有完美匹配层（PML）吸收体的非相容混合单元（四面体/六面体）不连续伽辽金时域（DGTD）方法来分析双周期结构的电磁散射。提出了一种基于辅助微分方程 (ADE) 的高效 PML 实现，其中包含由时域周期性边界条件 (PBC) 引入的变换场变量。所提出的 PML 实现在吸收高阶 Floquet 模式的波方面表现良好。此外，还引入了混合阶 DGTD 方法来提高所提出的 PML 实现的长期稳定性并降低总计算成本。基于混合四面体和六面体网格，非相容 DGTD 方法可以在复杂散射几何形状附近提供精确的场分布，同时减少其余计算域（包括开放空间和 PML 区域）的自由度 (DoF)。最后，电磁仿真证明了该方法的适用性、准确性和效率。
A nonconforming mixed-element (tetrahedral/hexahedral) discontinuous Galerkin time-domain (DGTD) method with a perfectly matched layer (PML) absorber is proposed to analyze the electromagnetic scattering from doubly periodic structures. An efficient auxiliary differential equation (ADE)-based PML implementation is presented with transformed field variables introduced by the time-domain periodic boundary conditions (PBCs). The proposed PML implementation performs well in absorbing the waves with high-order Floquet modes. Additionally, a mixed-order DGTD method is introduced to improve the proposed PML implementation’s long-term stability and reduce the total computational cost. Based on the mixed tetrahedral and hexahedral grids, the nonconforming DGTD method can provide accurate field distribution near complex scattering geometries while simultaneously reducing the degrees of freedom (DoF) in the rest of the computational domain, including the open space and PML regions. Finally, electromagnetic simulations are presented to demonstrate the applicability, accuracy, and efficiency of the proposed method.