Comparison of FT-FDTD and Spectral Domain FDTD for Periodic Structures
Comparison of FT-FDTD and Spectral Domain FDTD for Periodic Structures
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DOI：
10.1109/iwat.2008.4511317
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发表时间：
2008-03
期刊：
影响因子：
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通讯作者：
K. Toyoda;T. Uno;T. Arima
中科院分区：
文献类型：
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作者：
K. Toyoda;T. Uno;T. Arima
近年来，超材料及其在天线等领域的应用得到了广泛的理论和实验研究。超材料通常由导体和/或电介质/磁性材料组成的周期性结构来实现。为了正确设计超材料的特性，需要一些理论和/或数值技术。时域有限差分法因其能方便地分析各种复杂现象而被公认为是一种强有力的分析方法。此外，一些技术已经提出了使用FDTD方法分析周期性结构。其中之一是谱域FDTD方法。该方法算法简单，结果稳定，但一般只适用于单一频率。另一种是场变换法（FT-FDTD）。这种方法可以应用于脉冲响应，但需要一些附加的变量来实现周期性边界条件，为了简单起见，这种方法通常使用Mur吸收边界条件。由于需要较多的辅助变量，因此在PML吸收边界上的应用比较困难。此外，已经发现，当分析斜入射波时会发生一些不稳定性。在前半部分，谱域和FT-FDTD方法进行了简要回顾。第二部分分析了几种周期性结构，比较了FT-FDTD方法和谱域FDTD方法。
In recent years, the metamaterials and its applications to antenna and other fields have been widely investigated theoretically and experimentally. The metamaterials are usually realized by some periodic structures composed of a conductor and/or dielectric/magnetic materials. In order to design the characteristics of metamaterial properly, some theoretical and/or numerical techniques are required. The FDTD method is recognized as a powerful analyzing method for the metamaterials, because considerably, complicated phenomena can be analyzed easily. Furthermore, some techniques have been proposed to analyze the periodic structures using the FDTD method. One of which is the Spectral Domain FDTD method. This method has a very simple algorithm, and gives stable results, but this method can be applied only for a single frequency in general. The another one is called Field-Transformation (FT-FDTD)method proposed. This technique can be applied to a pulse response, but, requires some additional variables to realize a periodic boundary condition, The Mur's absorbing boundary condition is usually used in this method, for the simplicity. The application to the PML absorbing boundary is quite difficult because the more auxiliary variables are required. Furthermore, it has been found that some instability occurs when analyzing an oblique incident wave. In the first half, the spectral domain and FT-FDTD methods are briefly reviewed. In the second half, we analyze some periodic structures and we compare FT-FDTD method and spectral domain FDTD.