变换光学理论下天线特性的研究
发布时间：2019-01-21 18:33
【摘要】：变换光学理论的蓬勃发展,使得人们想要人为操纵光线传播的梦想成为现实。作为变换光学理论的核心方法——坐标变换法被逐渐地应用于电磁器件的研究,隐身衣就是其中一个典型的例子。随后有学者认为,坐标变换法可以为共形天线的研究提供新的理论指导。但是,目前的研究多是基于理想电磁源的等效,如何从理想电磁源过渡为实际天线的研究,是一个颇具挑战的难题。 本文基于变换光学理论,用坐标变换的方法和边界条件推导了天线馈电端口的切向馈电场的坐标变换公式。然后用了四种不同的天线模型来验证该公式的正确性,从而证明了基于变换光学方法的共形天线的研究的可行性。论文的主要研究工作和创新点可分为以下几个部分： 1.根据变换空间中等效理想电磁源的坐标变换公式,用边界条件和格林函数的方法,分别推导了线天线在馈电处切向馈电场的坐标变换公式和面天线在馈电端口处切向平面上的馈电场的坐标变换公式。推导结果显示,只需在天线的馈电处的切向馈电场遵循原本线电流或者面电流的变换方法,即可实现在坐标变换前后天线的辐射场保持一致的特性。该公式的提出,实现了从理想电磁源的共形变换到天线的等效共形变换的过渡。 2.通过理想二维情况下的线天线模型的提出,将天线的馈电公式用于二维理想线天线pinwheel模型,通过电磁仿真软件COMSOL对该模型进行仿真和结果分析,得出了天线在坐标变换前后辐射特性等效的结论,从而验证了天线馈电公式的正确性。 3.本文进一步提出了三维情况下的实际线天线模型,首先提出了球面偶极子天线模型,仿真得到变换后的天线的辐射场与原始偶极子天线的一致。然后又用埋藏式单极子天线模型来仿真验证变换前后天线的辐射等效性,并提出了一种简便的天线设计的方法。这两个模型不仅验证了线天线馈电方程的正确性,而且可以将理论联系实际,为实际工作中线天线的共形设计提供了理论上的可行性。 4.由于微带贴片天线在共形设计中的普遍应用,文中提出了平面微带贴片天线球面化的模型,仿真并验证了面天线切向馈电口面上馈电场的坐标变换公式的正确性。从仿真结果来看,天线实现了等效共形变换。由于在实际应用中,微带贴片天线的共形研究较多,因此,该模型的仿真在诸多研究方法中增添了一种更为简单和有效的方法。
[Abstract]:With the rapid development of transformational optics, the dream of manipulating the propagation of light becomes a reality. As the core method of transform optics theory, coordinate transformation method has been gradually applied to the study of electromagnetic devices. Stealth clothing is one of the typical examples. Subsequently, some scholars believe that coordinate transformation method can provide new theoretical guidance for the study of conformal antenna. However, the current research is mostly based on the equivalent of the ideal electromagnetic source. How to transition from the ideal electromagnetic source to the actual antenna is a challenging problem. Based on the theory of transformation optics, the coordinate transformation formula of the tangential feed field of the antenna feed port is derived by using the method of coordinate transformation and boundary conditions. Then four different antenna models are used to verify the correctness of the formula, which proves the feasibility of the research of conformal antenna based on transform optics. The main research work and innovation points can be divided into the following parts: 1. According to the coordinate transformation formula of the equivalent ideal electromagnetic source in the transformation space, the boundary condition and the Green's function method are used. The coordinate transformation formulas of the tangential feed field at the feed point and the coordinate transformation formula of the feed field on the tangential plane of the plane antenna at the feed port are derived respectively. The derivation results show that the radiation field of the antenna before and after coordinate transformation can be kept consistent as long as the tangential feed field at the antenna follows the original line current or surface current transformation method. The formula can realize the transition from the common deformation of the ideal electromagnetic source to the equivalent conformal transformation of the antenna. 2. The feed formula of the antenna is applied to the pinwheel model of the two-dimensional ideal wire antenna through the proposed linear antenna model under the ideal two-dimensional condition. The simulation and result analysis of the model are carried out by the electromagnetic simulation software COMSOL. The equivalent radiation characteristics of the antenna before and after coordinate transformation are obtained, and the correctness of the antenna feed formula is verified. 3. In this paper, the actual antenna model in 3D is proposed. Firstly, the spherical dipole antenna model is proposed. The radiation field of the transformed antenna is consistent with that of the original dipole antenna. Then the radiation equivalence of the antenna before and after the transformation is verified by the buried monopole antenna model, and a simple antenna design method is proposed. These two models not only verify the correctness of the wire antenna feed equation, but also combine the theory with practice, and provide the theoretical feasibility for the conformal design of the line antenna in practice. 4. Due to the general application of microstrip patch antenna in conformal design, a spherical model of planar microstrip patch antenna is proposed, and the correctness of the coordinate transformation formula of the feed field on the tangential feed surface of the plane antenna is verified by simulation. From the simulation results, the equivalent conformal transformation is realized. Because the conformal research of microstrip patch antenna is much more in practical application, the simulation of the model has added a simpler and more effective method in many research methods.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN820
本文编号：2412918
[Abstract]:With the rapid development of transformational optics, the dream of manipulating the propagation of light becomes a reality. As the core method of transform optics theory, coordinate transformation method has been gradually applied to the study of electromagnetic devices. Stealth clothing is one of the typical examples. Subsequently, some scholars believe that coordinate transformation method can provide new theoretical guidance for the study of conformal antenna. However, the current research is mostly based on the equivalent of the ideal electromagnetic source. How to transition from the ideal electromagnetic source to the actual antenna is a challenging problem. Based on the theory of transformation optics, the coordinate transformation formula of the tangential feed field of the antenna feed port is derived by using the method of coordinate transformation and boundary conditions. Then four different antenna models are used to verify the correctness of the formula, which proves the feasibility of the research of conformal antenna based on transform optics. The main research work and innovation points can be divided into the following parts: 1. According to the coordinate transformation formula of the equivalent ideal electromagnetic source in the transformation space, the boundary condition and the Green's function method are used. The coordinate transformation formulas of the tangential feed field at the feed point and the coordinate transformation formula of the feed field on the tangential plane of the plane antenna at the feed port are derived respectively. The derivation results show that the radiation field of the antenna before and after coordinate transformation can be kept consistent as long as the tangential feed field at the antenna follows the original line current or surface current transformation method. The formula can realize the transition from the common deformation of the ideal electromagnetic source to the equivalent conformal transformation of the antenna. 2. The feed formula of the antenna is applied to the pinwheel model of the two-dimensional ideal wire antenna through the proposed linear antenna model under the ideal two-dimensional condition. The simulation and result analysis of the model are carried out by the electromagnetic simulation software COMSOL. The equivalent radiation characteristics of the antenna before and after coordinate transformation are obtained, and the correctness of the antenna feed formula is verified. 3. In this paper, the actual antenna model in 3D is proposed. Firstly, the spherical dipole antenna model is proposed. The radiation field of the transformed antenna is consistent with that of the original dipole antenna. Then the radiation equivalence of the antenna before and after the transformation is verified by the buried monopole antenna model, and a simple antenna design method is proposed. These two models not only verify the correctness of the wire antenna feed equation, but also combine the theory with practice, and provide the theoretical feasibility for the conformal design of the line antenna in practice. 4. Due to the general application of microstrip patch antenna in conformal design, a spherical model of planar microstrip patch antenna is proposed, and the correctness of the coordinate transformation formula of the feed field on the tangential feed surface of the plane antenna is verified by simulation. From the simulation results, the equivalent conformal transformation is realized. Because the conformal research of microstrip patch antenna is much more in practical application, the simulation of the model has added a simpler and more effective method in many research methods.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN820
【参考文献】
相关期刊论文 前2条
1 赵刚;;共形天线及共形天线阵综述[J];大众科技;2009年01期
2 钟玲玲;邱景辉;白文静;王楠楠;;新型超宽带宽波束圆极化天线[J];哈尔滨工业大学学报;2007年05期
，本文编号：2412918
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