【作者】 张振辉；

【导师】 王政平；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2011， 博士

【摘要】 电磁超材料(Metamaterials)是一种通过在自然媒质中嵌入人工设计的几何结构的电磁单元,构造出自然媒质不具有的电磁特性的新型人工材料。目前,广泛研究的电磁超材料包括左手材料(介电常数与磁导率均为负值的材料)、电单负材料(介电常数为负值、磁导率为正值的材料)、磁单负材料(介电常数为正值、磁导率为负值的材料)、近零折射率材料(介电常数或磁导率值接近零的材料)、复合左／右手传输线等。在超材料中研究得最早也是研究得最多的是左手材料。由于电磁超材料具有许多奇异的电磁学特性,从而该类材料在许多领域具有巨大的、潜在的应用前景。本论文主要研究的内容是基于Metamaterials的微波吸波器和滤波器的基本理论与设计方法,主要工作如下：(1)对电磁超材料的电磁性能做了系统的理论分析,推导出了电磁波在左手单层介质,左、右手双层介质结构中传输的理论公式,获得了波阻抗与电磁超材料的电磁参量、结构参量和电磁波的频率之间的相互关系。(2)提出了用电磁超材料制作吸波器的基本设想,给出了多种基于电磁超材料的微波吸波体的设计理论与方法和设计示例。(3)依据磁超材料基本理论,研究了基于单负对结构的透射型滤波器和反射型滤波器的设计理论与设计方法,推导出了透射型滤波器和反射型滤波器的滤波性能与电磁超材料的电磁参量、介质层厚度及介质层厚度比与中心频率和滤波器带宽之间的关系。对用电磁超材料制作的透射型滤波器和反射型滤吸波器的理论模型做了仿真,对仿真结果的物理含义做了诠释。仿真结果验证了电磁超材料的电磁参量、介质层厚度及介质层厚度比与滤波器中心频率和带宽之间的关系。(4)研究结果表明所设计的滤波器在某些频带内具有良好的滤波性能,通过调节等效元件参量可在一定范围内调整该滤波器的中心频率与带宽,为工程设计提供了参考。更多还原

【Abstract】 Metamaterials are new artificial materials with some electromagnetic properties that natural medium do not own, by artificially embedding designed electromagnetic cell units in the natural medium. At present, left-handed materials (LHM) (the materials with negative permittivity and permeability),εsingle-negative materials (the materials with negative permittivity and positive permeability),μsingle-negative materials (the materials with positive permittivity and negative permeability), near-zero refractive index materials (the materials with the permittivity or permeability approach to zero), composite left/right handed transmission line, and so on. The left handed materials are those one that are studied earliest and also most among the metamaterials. Due to the fantastic electromagnetic properties of metamaterials, these materials have huge and promising applications in many fields. This paper mainly studied the theories of wave-absorbers and filters based on metamaterials, of which the innovative points as following:(1) The theoretical analysis on the electromagnetic performance of metamaterials was studied, giving the transmission formula of electromagnetic wave in the LHM single-layer medium, and RHM double-layer medium structures, and obtaining the mutual relationships among the wave impedance, electromagnetic parameters of metamaterials, and the electromagnetic frequency.(2) The basic idea to design absorbers using metamaterials was proposed, giving the design principles and methods of microwave absorbers based on many kinds of metamaterials, and the design examples.(3) The design theories and methods of transmission-type and reflection-type filters based on single-negative structures were studied following the basic theory of metamaterials, deducing the relationships between the filtering performance of transmission-type/reflection-type filters and the electromagnetic parameters, thickness of medium, the ratio of medium thickness, center frequency and filter bandwidth of the metamaterials. We completed the simulation of theoretical model for the transmission-type and reflection-type filters made from metalmaterials, and gave the interpretations of physical meanings for simulating results. The simulation results confirmed the relationships between electromagnetic parameters, thickness of medium, the ratio of medium thickness, the center frequency and filter band width.(4) The study shows that the designed filters own perfect filtering performance within some certain frequency bands, and the center frequency and band width can be adjusted by regulating the parameters of equal elements within some range, providing the reference for the engineering design.更多还原