共查询到20条相似文献,搜索用时 15 毫秒
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本文基于椭圆柱谐基函数展开,对非同轴任意多层介质椭圆柱体的电磁散射进行了严格地电磁场分析,利用Mathieu函数及其加法定理,在各层边界面上进行场的匹配,获得了任意方面斜入射电磁波下电磁散射解析解。 相似文献
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Qingqi Pei Tunyang Lee Liaojun Pang 《Journal of Infrared, Millimeter and Terahertz Waves》2010,31(9):1091-1099
We propose an analytical approach to characterize the role of anisotropic ratio in the light scattering of spherical layers
with spherical anisotropy defined in spherical coordinates. Single-layer model, thin-film coating, and a collection of such
spherical particles are all treated analytically, with the emphasis on the role of anisotropy in the scattering properties.
Two types of anisotropic potentials are established to take into account the electric and magnetic anisotropy ratios (AR)
which are fundamental to represent the electromagnetic fields in the presence of spherical polar crystallites. This paper
provides a new method to depict the particle-illumination interaction at a macroscopic view, and gives new insight to the
study of anisotropic interaction of particularly oriented molecular layers, elucidating the importance of anisotropy ratios
in the scattering control. 相似文献
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本文给出了研究任意形状三维磁各向异性目标电磁散射问题的一种混合计算方法。该方法以磁场作为未知函数建立频域体积分 微分方程 ,使用脉冲基函数和点匹配函数的矩量法 (MOM)将之转化为线性代数方程组。在求解过程中应用共轭梯度法 (CGM)和快速傅立叶变换 (FFT)相结合的方法降低所需计算机内存和CPU时间。对均匀磁各向同性球的数值计算结果与相应Mie理论结果吻合较好。在此基础上给出了磁各向异性球和立方体的雷达散射截面。计算结果表明该计算方法兼容性强 ,是一种求解三维电磁散射问题的有效途径。 相似文献
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变换电磁学是近几年来电磁领域的研究热点。利用坐标变换方法,能够在一定程度上人为调控电磁波的传播路径,结合超材料技术,可以设计出多种具有奇特功能的新颖电磁器件。该文对一系列折线型坐标变换器件做了归纳总结,主要讨论了其中的电磁波集中器;在此基础上从内置隐身飞机模型的散射截面角度进一步研究了电磁波集中器的散射放大功能及其在军事上的应用;最后对该器件参数极值及其归一化分布范围进行了详细的分析。 相似文献
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D. B. Demin A. I. Kleev A. G. Kyurkchan 《Journal of Communications Technology and Electronics》2018,63(6):505-511
An approximate approach based on application of the pattern equation method is developed for solution of the problem of scattering by a thin cylinder. Explicit formulas for integral scattering characteristics that are applicable to cylindrical scatterers of a complex shape are derived. The accuracy of these formulas is controlled by checking fulfillment of the “optical theorem.” 相似文献
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该文用球矢量波函数对各向异性铁氧体介质涂覆导体球的电磁散射解析解开展研究。各向异性铁氧体介质中电磁场的球矢量波函数解可表示成第一、二、三、四类球矢量波函数之和。根据球Bessel函数的性质,可以得出导体球涂覆各向异性铁氧体介质的球矢量波函数解析解。应用铁氧体与自由空间分界面上电磁场切向连续和在导体球面上切向电场等于零的边界条件以及球矢量波函数切向正交性质,可分别得出铁氧体介质中电磁场和散射场的展开系数。给出了平面波入射情况下的数值计算结果。该文的结果可应用于有关微波器件、天线以及目标特征的分析和计算。 相似文献
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T. Idehara I. Ogawa K. Kawahata H. Iguchi K. Matsuoka 《Journal of Infrared, Millimeter and Terahertz Waves》2004,25(11):1567-1579
Gyrotron FU II has been successfully applied as a submillimeter wave radiation source to plasma scattering measurements on the Compact Helical System (CHS) in National Institute for Fusion Science (NIFS) in Japan. The gyrotron operates in a long pulse mode (the pulse width is about 600 ms) at a frequency of about 350 GHz (the corresponding wavelength is 0.85 mm). The output power is about 110 W. The output power is transmitted along a circular waveguide system and converted to a Gaussian-like beam by a quasi-optical antenna. After that, the beam is directed onto the CHS plasma and the scattered signal is detected by a homodyne detection system. The frequency and the wave number of the scattered signal are analyzed. The results suggest that a broad band low frequency (several tens to several hundreds kHz) density fluctuation is excited in the CHS plasma only during neutral beam injection (NBI) or ion cyclotron resonance (ICR) heating. 相似文献
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K. F. Tsang L. Mo Z. B. Ye 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(6):1005-1022
In this paper, both fast Fourier transformation (FFT) and preconditioned CG technique are introduced into method of lines (MOL) to further enhance the computational efficiency of this semi-analytic method. Electromagnetic wave scattering by an infinite plane metallic grating is used as the examples to describe its implementation. For arbitrary incident wave, Helmholz equation and boundary condition are first transformed into new ones so that the impedance matrix elements are calculated by FFT technique. As a result, this Topelitz impedance matrix only requires O(N) memory storage for the conjugate gradient FFT method to solve the current distribution with the computational complexity O(N log N) . Our numerical results show that circulate matrix preconditioner can speed up CG-FFT method to converge in much smaller CPU time than the banded matrix preconditioner. 相似文献
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R. S. Chen K. F. Tsang Edward K. N. Yung 《Journal of Infrared, Millimeter and Terahertz Waves》2000,21(8):1281-1301
In this paper, symmetric successive overrelaxation (SSOR) preconditioned CG technique are introduced into method of lines (MOL) to further enhance the computational efficiency of this semi-analytic method. Millimeter wave scattering by an infinite plane metallic grating is used as the examples to describe its implementation, whose analysis usually needs fast algorithms because of electrically large dimension. For arbitrary incident wave, Helmholz equation and boundary condition are used to calculate the impedance matrix and then to obtain reduced current-voltage linear matrix equation in spatial domain. An effective symmetric successive overrelaxation preconditioned conjugate gradient iterative method, SSOR-PCG, is chosen to solve this matrix equation. With SSOR as the preconditioner as well as its efficient implementing in CG algorithm, PCG method can converge to accurate solution in much fewer iteration steps. 相似文献
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《Antennas and Propagation, IEEE Transactions on》2010,58(1):51-58
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An error detecting data test set with a pseudorandom bit test pattern is analyzed using generating functions. A modification to the common design that combines the advantages of automatic and manual synchronization modes is proposed; it provides automatic synchronization and records one error count for each bit in error. 相似文献
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分析无限平面金属栅电磁散射问题的一种新方法 总被引:6,自引:1,他引:5
本文基于直线法和Floquet定理提出了一种分析无限平面金属栅周期结构电磁散射问题的新方法。数值结果与谱域法结果和实验结果一致,但本文方法具有数学模型简单,计算量小等优点。 相似文献
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为了降低Yee氏蛙跳式网格划分的台阶误差,该文对3维曲面导体目标进行精确电磁建模,将时域多分辨(MRTD)算法与共形时域有限差分(CFDTD)算法结合,提出一种新的基于Daubechies尺度函数的共形时域多分辨(CMRTD)方法。该文提出将基于Daubechies尺度函数的MRTD迭代公式分解为若干传统FDTD迭代公式的线性组合,然后对最里面回路上的FDTD分解式运用局部共形技术,再将各个分解式进行线性组合,从而得到CMRTD结果。仿真结果表明,CMRTD方法既保持了MRTD方法节省计算资源、计算效率高等优点,同时明显提高了计算的精度。 相似文献