复杂媒质的电磁特性分析

【作者】 曹海平；

【导师】 陈如山；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2008， 硕士

【摘要】 分析复杂媒质的电磁特性对工程研究具有重要的理论和实用价值。复杂媒质包括各向异性煤质、双各向同性媒质、双各向异性媒质,其中双各向异性媒质是最一般的线性媒质。复杂媒质特性复杂且多为人工合成材料,工艺复杂,难度大,实验成本高且周期长,这时借助有效的电磁仿真就显得必要和迫切。近年来,随着计算机和现代科学技术的发展,如何准确分析复杂媒质目标体的电磁特性,一直是计算电磁学领域的研究热点。本文首先介绍了铁氧体材料的特性,在矢量有限元方法基础上,实现了铁氧体环行器的环行特性仿真分析:在合元极方法基础上,深入研究并推导了适用于铁氧体、等离子体、手征材料等复杂媒质的通用泛函及变分表达式,使得复杂媒质的统一建模成为可能,并进一步分析计算了位于自由空间中的各类复杂媒质体的电磁散射特性;迫于目标与环境一体化建模的需要,本文还研究了位于半空间中的复杂媒质体的散射特性,并引入曲面基函数,从而为准确拟合曲率较大的目标体提供了一条有效途径。此外,本文还研究了覆盖等离子体层的金属平板,其反射系数随等离子相关参数变化的一些特性。本文通过与其它理论方法结果的比较,验证了本文理论的正确性。更多还原

【Abstract】 It has practical and theory value to analyze electromagnetic scattering from the complex medium target in the project. Complex materials include chiral, anisotropic and bi-anisotropic media. In the complex materials, the bi-anisotropic media is the most general linear material with complicated characteristic .Especially, the process of producing the complex material is difficult, high cost and long period. So, it is needed to employ the analysis of electromagnetic .Recently, analysing scattering from the complex material targets has become more and more popular with the development of computers and modern science and technologies.Firstly, the paper introduced the character of the ferrite and simulated electromagnetic characteristic of the circulator based on the finite element method (FEM); Nextly, the paper studied the formula which can be used in anisotropic, bi-isotropic, bi-anisotropic materials, such as ferrite、plasma、chiral and so on , achieving unity modeling of complex materials. Further more, based on FEBI(Finite element boundary integral method),the paper also analyze the character of electromagnetic scattering from complex medium target in a free space .With the requirement of unity modeling between target and environment , the paper also studied scattering from complex materials target above a lossy half space , and introduced the curve basic function .Consequently, the curve basic function could supply an effective approach for modeling target which has bigger curvature . Lastly, the paper also studied the reflection coefficient of the PEC plate covered plasma , which changes with the parameters of the plasma. In this paper, the numerical results are in agreement with the published data.更多还原