利用有源超材料调控电磁波传播特性的研究

发布时间：2018-12-07 15:54

【摘要】：近年来,关于左手材料、近零折射率材料、光子晶体等人工电磁超材料的研究与应用越来越引人关注。其独特的电磁特性(如近零折射率、负折射率等)必将被广泛应用于天线卫星、军事武器材料、微波与毫米波电路元件、军事隐形等领域。而在这些研究与应用中往往出现许多独特的行为,因此电磁波在媒质界面及其内部的传播行为成为一个热门的研究方向。通常,介电常数和磁导率这两个电磁参数往往被用于研究电磁超材料的特性。本文通过对这两个物理量及其波阻抗η=(?)=(?)的调控,与左手材料、近零折射率材料、光子晶体等人工电磁超材料特性作对比,对电磁波在阻抗实部为零的有源超材料(ZRPIM)表面及其内部的传播特性进行了研究。首先探讨了在阻抗实部为零有源超材料表面电磁波异常的反射特性,通过建立光疏媒质到光密媒质(且为ZRPIM)的理论模型,并基于麦克斯韦方程组和反射折射关系式,考察了在ZRPIM表面上电磁波出现的全角全反射、反射增强行为。然后探讨在在阻抗实部为零有源超材料平板内电磁场能量转化与电磁波传播特性,发现正是由于平板中前向波和后向波之间的相互干扰,或称坡印廷矢量的交叉项起着主导作用,从而导致奇异行为的出现。通过对瞬时能流密度、电磁能量损耗密度、电磁场储能密度等参量特性之间关系的仔细考虑,推导出%健S(z,t)](坡印廷矢量的梯度)和We,m(z,t)(电场做功和磁场做功之和)的相等关系,验证了能量守恒定律,也进一步表明了此理论模型的自洽性。最后通过调节介电常数和磁导率分别对具有低阻抗实部有源超材料特性的无损材料、有损材料、增益材料进行了数值模拟,初步验证了正是由于此交叉项而导致的一些新颖特性。
[Abstract]:In recent years, the research and application of artificial electromagnetic metamaterials such as left-handed materials, near-zero refractive index materials and photonic crystals have attracted more and more attention. Its unique electromagnetic properties (such as near-zero refractive index, negative refractive index, etc.) will be widely used in antenna satellites, military weapon materials, microwave and millimeter wave circuit elements, military stealth and so on. However, there are many unique behaviors in these researches and applications, so the propagation behavior of electromagnetic waves at the interface and inside of the medium has become a hot research direction. In general, permittivity and permeability are often used to study the properties of electromagnetic metamaterials. In this paper, the two physical quantities and their wave impedance 畏 = (?) Compared with the characteristics of artificial electromagnetic metamaterials such as left-handed material, near-zero refractive index material and photonic crystal, the propagation characteristics of electromagnetic wave on the surface and inside of active metamaterials with zero impedance are studied. The reflection characteristics of electromagnetic wave anomalies on the surface of zero active metamaterials in real impedance are discussed. By establishing a theoretical model from light thinning medium to light dense medium (and ZRPIM), and based on Maxwell equations and reflection refraction relation, The total angle reflection and reflection enhancement behavior of electromagnetic waves on ZRPIM surface are investigated. Then, the characteristics of electromagnetic energy conversion and electromagnetic wave propagation in a plate with zero active metamaterials at the real impedance are discussed. It is found that the interaction between forward and backward waves in the plate is precisely due to the interaction between forward and backward waves. The cross-term of Poynting vector plays a leading role, leading to the emergence of strange behavior. Through careful consideration of the relationship between the instantaneous energy flow density, the electromagnetic energy loss density, the electromagnetic energy storage density and other parameter characteristics, we derive the% Jian S (zt)] (gradient of Poynting vector) and We,m (z). The equal relationship between the work done by the t) (electric field and the work done by the magnetic field verifies the conservation law of energy and further indicates the self-consistency of the theoretical model. Finally, by adjusting the permittivity and permeability, numerical simulation of lossless material, lossy material and gain material with the characteristics of active metamaterials with low impedance are carried out, respectively. Some novel properties caused by this cross term are preliminarily verified.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34;O441

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