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磁化等离子体的并行三维JEC-FDTD算法及其应用 总被引:2,自引:1,他引:1
给出了三维磁化等离子体的电流密度卷积-时域有限差分(JEC-FDTD)算法的迭代公式,指出该算法与一般FDTD算法实现并行时的不同:增加了电流密度的迭代,以及并行计算时在子域交界面上增加了一些数据的交换.并实现了基于MPI (Message Passing Interface)的并行JEC-FDTD算法.然后用计算涂覆等离子体的金属球的雷达散射截面(RCS)的算例验证了并行程序的可靠性,并测试了并行程序在某集群上的并行效率.最后计算了涂敷磁化等离子体的全尺寸飞机的单站RCS.结果表明并行JEC-FDTD算法是可靠的,而且并行效率高,能计算各向异性磁化等离子体的电大尺寸目标的散射. 相似文献
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本文将电流密度卷积时域有限差分(Current Density Convolution Finite Difference Time Domain,JEC-FDTD)方法扩展到求解任意磁偏角电磁波在磁化等离子体中的传播和共振吸收问题.首先,验证数值算法正确性,分析了法拉第旋转角效应,以及任意磁偏角电磁波在等离子体中的传播特性.然后,求解电磁波在磁化等离子体中的等离子体朗缪尔共振、电子回旋共振、高频混杂共振吸收特性.结合在电离层加热中的应用,重点分析了等离子体高频混杂共振吸收特性,得到了高频混杂共振激发的频率匹配条件.数值结果表明,高频混杂共振吸收是电离层加热的有效方式,对于解释电离层加热机制具有重要意义. 相似文献
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Shaobin Liu Jinjun Mo Naichang Yuan 《Microwave and Wireless Components Letters, IEEE》2004,14(5):222-224
The piecewise linear current density recursive convolution (PLCDRC) finite-difference time-domain (FDTD) method for isotropic dispersive media greatly improves accuracy over recursive convolution (RC) and current density recursive convolution (CDRC) FDTD approaches but retains its speed and efficiency advantages. This letter extends this approach to anisotropic magnetoactive plasmas which incorporates both anisotropy and frequency dispersion at the same time, enabling the transient solutions of electromagnetic wave propagation in anisotropic magnetoactive plasmas. The high efficiency and accuracy of the method are confirmed by computing the reflection and transmission through a magnetized plasma layer, with the direction of propagation parallel to the direction of the biasing field. A comparison to frequency-domain analytic results and CDRC FDTD results is included. 相似文献
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Hunsberger F. Luebbers R. Kunz K. 《Antennas and Propagation, IEEE Transactions on》1992,40(12):1489-1495
When subjected to a constant magnetic field, both plasmas and ferrites exhibit anisotropic constitutive parameters. For electronic plasmas this anisotropy must be described by using a permittivity tensor in place of the usual scalar permittivity. Each member of this tensor is also very frequency dependent. A finite-difference time-domain formulation which incorporates both anisotropy and frequency dispersion, enabling the wideband transient analysis of magnetoactive plasma, is described. Results are shown for the reflection and transmission through a magnetized plasma layer, with the direction of propagation parallel to the direction of the biasing field. A comparison to frequency-domain analytic results is included 相似文献
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Shaobin Lui Jinjun Mo Naichang Yuan 《Journal of Infrared, Millimeter and Terahertz Waves》2002,23(12):1803-1815
A novel finite-difference time-domain (FDTD) methodology which incorporates both anisotropy and frequency dispersion at the same time is developed for electromagnetic wave propagation in anisotropic magnetoactive plasmas in this paper. The numerical verification of the method are confirmed by computing the reflection and transmission of right-handed/left-handed circularly polarized (RCP/LCP) wave through a magnetized plasma layer, with the direction of propagation parallel to the direction of the biasing field. And, the right-handed / left-handed polarized wave reflection coefficients for electromagnetic signals normally incident upon a conductive plane covered with a layer of magnetized plasma are computed using the new FDTD method. The parabolic electron-number density profile varies only in the direction perpendicular to the plane. The function dependence of reflection coefficients on the number density, collision frequency and external magnetic field is studied. 相似文献
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为了研究温度、密度对磁化等离子体光子晶体禁带特性的影响,采用在等温近似的条件下,磁化等离子体的分段线形电流密度卷积时域有限差分算法研究了1维磁化等离子体光子晶体的禁带特性。以高斯脉冲为激励源,用算法公式得到的电磁波透射系数来讨论了温度、等离子体层密度对其禁带特性的影响。结果表明,改变温度和等离子体层密度分布可以实现对禁带的控制。 相似文献
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电磁波和磁化等离子体的非线性相互作用复杂,高功率电磁波调控电离层实验提供了研究非线性基本问题的主动方式.为构建空间磁化等离子体受激电磁辐射(stimulated electromagnetic emissions,SEEs)体系,本文首先总结了磁化等离子体中可能发生的参量不稳定性;其次,回顾了近十年国际电离层加热激发S... 相似文献
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Shaobin Liu Wei Hong Naichang Yuan 《Journal of Infrared, Millimeter and Terahertz Waves》2006,27(3):403-423
The plasma photonic crystal is a periodic array composed of alternating thin unmagnetized (or magnetized) plasmas and dielectric materials (or vacuum). In this paper, the piecewise linear current density recursive convolution finite-difference time-domain method for the simulation of isotropic unmagnetized plasma is applied to model unmagnetized plasma photonic crystal structures. A perfectly matched layer absorbing material is used in these simulations. In time-domain, the electromagnetic propagation process of a Gaussian pulse through an unmagnetized plasma photonic crystal is investigated. In frequency-domain, the reflection and transmission coefficients through unmagnetized plasma photonic crystals are computed and their dependence on plasma frequency, plasma thickness, collision frequency is studied. The results show theoretically that the electromagnetic bandgaps of unmagnetized plasma photonic crystals are tuned by the plasma parameters. 相似文献
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An efficient method to include frequency-dependent materials in finite difference time domain calculations based on the recursive evaluation of the convolution of the electric field and the susceptibility function has previously been presented. The method has been applied to various materials, including those with the Debye, Drude, and Lorentz forms of complex permittivity, and to anisotropic magnetized plasmas. Previous demonstrations of this approach have been confined to total field calculations in one dimension. In this paper the recursive convolution method is extended to three-dimensional scattered field calculations. The accuracy of the method is demonstrated by calculating scattering from spheres of various sizes composed of three different types of frequency-dependent materials 相似文献
14.
Lixia Yang 《Journal of Infrared, Millimeter and Terahertz Waves》2007,28(7):557-565
The finite-difference time-domain method based on recursive convoltion method (RC-FDTD) for the electric anisotropic dispersive medium is discussed in detail. To exemplify the availability of the three-dimensional RC-FDTD algorithm, the backscattering Radar-Cross-Section(RCS) of a non-magnetized plasma sphere is computed, and the numerical results are the same as the one of the Shift Operater-FDTD method, and show that the RC-FDTD method is correct and efficient. In addition, the co-polarized and cross-polarized backscattering time-domain of a magnetized plasma sphere are obtained by the RC-FDTD algorithm. The results show that when the external magnetic field is implemented, the cross-polarized component appear, evidently. 相似文献
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《Antennas and Propagation, IEEE Transactions on》1991,39(1):29-34
Previous FDTD (finite-difference time-domain) formulations were not capable of analyzing plasmas for two reasons. First, FDTD requires that at each time step the permittivity and conductivity be specified as constants that do not depend on frequency, while even for the simplest plasmas these parameters vary with frequency. Second, the permittivity of a plasma can be negative, which can cause terms in FDTD expressions to become singular. A novel FDTD formulation for frequency-dependent materials (FD)2TD has been developed. It is shown that (FD) 2TD can be applied to compute transient propagation in plasma when the plasma can be characterized by a complex frequency-dependent permittivity. While the computational example presented is for a pulse normally incident on an isotropic plasma slab, the (FD)2TD formulation is fully three-dimensional. It can accommodate arbitrary transient excitation, with the limitation that the excitation pulse must have no zero frequency energy component. Time-varying electron densities and/or collision frequencies could also be included. The formulation presented is for an isotropic plasma, but extension to anisotropic plasma should be fairly straightforward 相似文献
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Keith G. Balmain 《电信纪事》1979,34(3-4):273-283
The last five years have witnessed remarkable progress in the theory and measurement of both the radiation and impedance properties of antennas in plasmas. Increased motivation for research in this area has been provided by the Space Shuttle program and by the prospect of nuclear fusion. The focus of attention has been on resonance cones in linear, anisotropic plasmas, including radiation patterns, wave interference, pulse propagation, reflections from boundaries and inhomogeneous media effects. Under nonlinear conditions, the focussed field of a resonance cone can significantly depress the plasma density. Under both linear and nonlinear conditions, the input impedance of dipole and loop antennas has been studied extensively, for both anisotropic and isotropic plasmas. A continuing challenge has been the as-yet-not-fully-explained experimental observation of linear, non-collisional enhanced resistivity of the sheath region around an antenna. Numerical impedance calculations employing simplified velocity distributions have shown particular promise. Ion and electron wave radiation patterns for various antenna shapes have been calculated and checked experimentally. The response of both single antennas and pairs of antennas to plasma fluctuations has been studied and found to have applications to plasma diagnostics. 相似文献
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Semiconductors - The propagation of solitary acoustic pulses in magnetized quantum electron–hole plasmas of semiconductors has been studied. The effects of an external magnetic field and... 相似文献
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Galerkin's method in the Hankel transform domain (HTD) is applied to the determination of the radar cross section (RCS) of a circular microstrip patch printed on a substrate which may be an uniaxial anisotropic dielectric, a magnetized ferrite, or a chiral material. The results obtained for circular patches on magnetized ferrites show that the RCS of these patches can be substantially reduced in a tunable frequency band when a bias magnetic field is applied. It is also shown that the results obtained for the RCS of circular patches printed on chiral materials can be substantially different from those obtained when substrate chirality is ignored 相似文献
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Huang Shoujiang Li Fang 《电子科学学刊(英文版)》2006,23(1):113-116
The electromagnetic propagation through an inhomogeneous magnetized plasma slab is studied using the Z-transform formulation of the Finite-Difference Time-Domain(FDTD) method. The direction of electromagnetic propagation is parallel to the biasing magnetic filed. To validate the Z-transform algorithm, the reflection and transmission coefficients for the right-hand circularly polarized wave of the homogeneous magnetized plasma slab are computed by means of discrete Fourier transform. The comparison between the reflection and transmission coefficients of the homogeneous plasma slab and analytical values indicates that Z-transform algorithm is very accurate. When the plasma frequency varies according to the square root and parabolic relations, the reflection and transmission coefficients of the inhomogeneous magnetized plasma slab are computed. 相似文献