Transformation Optics-Based Finite Difference Time Domain Algorithm for Scattering From Object With Thin Dielectric Coating
Transformation Optics-Based Finite Difference Time Domain Algorithm for Scattering From Object With Thin Dielectric Coating
复制标题
基于变换光学的有限差分时域算法用于薄介电涂层物体的散射
DOI：
10.1109/access.2019.2947276
复制
发表时间：
2019-10
期刊：
影响因子：
3.9
通讯作者：
Lei Kuang
中科院分区：
文献类型：
--
作者：
Lei Kuang
适当的介质涂层可以显著降低导电物体的电磁散射，使其无法被雷达探测到。然而，当物体包含薄涂层时，在传统的时域有限差分（FDTD）算法中需要精细的网格尺寸来离散薄涂层，这显著增加了存储量和计算时间。为了克服这一困境，我们提出了一种基于变换光学的FDTD（TO-FDTD）算法，以加速解决薄介质涂层的目标的电磁散射。本文提出了两种新的TO-FDTD模型，分别用于涂层圆柱和涂层任意多边形圆柱。通过坐标变换，物体的尺寸保持不变，而其薄涂层被扩大为厚涂层，这意味着可以用均匀粗网格代替细网格的FDTD算法进行模拟。通过求解雅可比变换矩阵，可以得到变换后的材料参数在变换区域内的不均匀性和各向异性。然后，我们开发了一个稳定的FDTD算法求解各向异性麦克斯韦方程。采用本文提出的TO-FDTD算法分别求解了涂覆圆柱和涂覆多边形圆柱的双站散射。TO-FDTD算法的计算结果与精确值和商业软件Comsol的计算结果吻合较好。数值实验验证了该算法的计算效率和精度。数值结果表明，在相同的粗网格尺寸下，TO-FDTD算法的计算精度高于无法模拟涂层吸波特性的传统FDTD算法。在相同精度水平下，本文提出的TO-FDTD方法比传统的细网格FDTD方法的计算效率提高了62-63倍。
A proper dielectric coating can reduce the electromagnetic scattering of the conducting object significantly so that it cannot be detected by the radar. However, when the object contains a thin coating, fine grid size is needed to discretize the thin coating in the conventional finite-difference time-domain (FDTD) algorithm, which increases the amount of memory and computational time significantly. To overcome this dilemma, we present a transformation optics-based FDTD (TO-FDTD) algorithm to accelerate the solution of electromagnetic scattering from objects with thin dielectric coatings. Two kinds of novel TO-FDTD models are proposed in this paper for a coated cylinder and a coated arbitrary polygonal cylinder, respectively. Through coordinate transformation, the size of the object remains unchanged while its thin coating is enlarged to a thicker one, meaning that it can be simulated by the FDTD algorithm with uniform coarse grids instead of fine grids. The transformed material parameters become inhomogeneous and anisotropic in the transformed region, which can be obtained by solving a Jacobian transformation matrix. We then develop a stable FDTD algorithm for solving anisotropic Maxwell’s equations. Bistatic scatterings of coated cylinders and a coated polygonal cylinder are solved by the TO-FDTD algorithm proposed in this paper, respectively. The result of the TO-FDTD algorithm matches well with the exact value and the result of the commercial software Comsol. The computational efficiency and accuracy of the proposed TO-FDTD algorithm are validated by numerical experiments. Numerical results show that the TO-FDTD algorithm has higher computational accuracy than the conventional FDTD algorithm that fails to simulate the absorbing property of the coating, when the same coarse grid size is used in the simulation. Under the same level of accuracy, the proposed TO-FDTD method can improve the computational efficiency by 62-63 times than the conventional FDTD method with fine grids in the simulations in the paper.
登录
查看更多内容
影响因子：
5.7
作者：
Jin Yan;D. Jiao
通讯作者：
Jin Yan;D. Jiao
影响因子：
6.7
作者：
Shiquan He;Z. Nie;Jun Hu
通讯作者：
Shiquan He;Z. Nie;Jun Hu
不完全 Cholesky 分解预条件 Krylov 子空间方法在三维电磁散射问题矢量有限元法中的应用
影响因子：
6.3
作者：
Ting-Zhu Huang;Yong Zhang;Liang Li;Yan-Fei Jing
通讯作者：
Yan-Fei Jing
影响因子：
5.7
作者：
P. Huddleston;L. Medgyesi-Mitschang;J. Putnam
通讯作者：
P. Huddleston;L. Medgyesi-Mitschang;J. Putnam
影响因子：
5.7
作者：
L. Medgyesi-Mitschang;J. Putnam
通讯作者：
L. Medgyesi-Mitschang;J. Putnam