A New High Order Finite Difference Time Domain Method
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摘要:
相比于传统高阶时域有限差分算法(FDTD)而言,该文提出了一种改进的高阶FDTD的优化方法,该算法基于安培环路定律,通过计算机技术寻找到一组最优的系数使得FDTD方法的全局色散误差达到最小,通过不同分辨率下的点源辐射模拟证明了该方法在较低分辨率的情况下仍然具有极低的相位误差,对于解决电大尺寸结构建模中的数值色散等问题提供了有效的解决方案。
Abstract:Compared with the traditional high-order Finite Difference Time Domain(FDTD) Method, an improved high-order FDTD optimization method is proposed in this paper. This algorithm is based on Ampere’s law of circuits and finds a set of optimal coefficients through computer technology to minimize the global dispersion error of the FDTD method.The simulation of point source radiation with different resolutions shows that this method still has very low phase error in the case of lower resolution. It provides an effective solution to the problem of numerical dispersion in the modeling of large size structures.
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Key words:
- Finite Difference Time Domain(FDTD) /
- Phase error /
- Optimization algorithm /
- Ampere’s law
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表 1 部分分辨率的色散误差
R K1 K2 ${\varPhi _{\gamma_i} }$ 5 –0.14493668 0.102073777 5.3797×10–10 10 –0.11619507 0.073446898 9.1959×10–14 15 –0.11180257 0.069281772 8.4433×10–16 20 –0.11032252 0.067892310 2.2994×10–17 25 –0.10964732 0.067260967 4.3034×10–18 30 –0.10928263 0.066920442 1.5703×10–19 35 –0.10906389 0.066716504 4.4814×10–20 表 2 4种情况下的运行时间和占用内存对比
FDTD
方法运行
时间(s)占用
内存(MB)空间
步长(m)时间
步长(s)粗网格 S22 0.0356 0.1 0.100 0.16×10–9 S24 0.0323 0.2 0.100 0.16×10–9 M24 0.0329 0.7 0.100 0.16×10–9 细网格 S22 77.3070 3.0 0.004 0.66×10–10 -
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