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1.
Tao Pan Guo-Ding Xu Tao-Cheng Zang Lei Gao 《Applied Physics A: Materials Science & Processing》2009,95(2):367-372
We have numerically studied the characteristics of a slab waveguide loaded with dispersive anisotropic metamaterials. For
two typical-structured metamaterials, we have analyzed the tensor expressions of frequency-dependent permittivity and permeability
and discussed influences of the resonant cell structures on waveguiding characteristics. Numerical results show that the slab
waveguide loaded with anisotropic metamaterials may, to some extent, behave as the slab waveguides of isotropic left-handed
metamaterials (LHMs) core and conventional right-handed materials core. To one’s interest, some unusual properties are revealed
in this paper, such as the coexistence of the fundamental guided mode and negative group velocity, and extraordinarily large
normal or anomalous group velocity dispersion. Our results may find some potential applications in both linear and nonlinear
optical technology. 相似文献
2.
基于用一种结构同时实现材料介电常数和磁导率为负的思想,提出了H型结构单元左手材料模型.采用矩形波导法测试表明,H型结构单元在微波频率范围出现左手透射峰,并且可以由参数t对左手特性区域进行调控.同时利用相位法、棱镜折射法和散射参量法从实验和理论证明了在左手透射峰区域材料的折射率为负值,介电常数和磁导率亦同时为负.相对由金属开口谐振环与金属线两种结构组合实现的左手材料,H型结构集磁谐振与电谐振于一体,结构简单、制备方便,对微波器件左手材料表现出更多的优越性. 相似文献
3.
通过理论分析和实验仿真,研究了用双环开口谐振环对(double split-ring resonator pairs,DSRRP)实现平面左手超材料的原理,用等效电路理论解释并描述了其负介电常数和负磁导率的产生机理,并对DSRRP在3维左手超材料设计的应用进行了探索性研究.结果表明,DSRRP可以实现小尺寸的平面左手超材料,此外,DSRRP还可以作为用以实现3维左手超材料负磁导率的3维各向异性磁超材料.
关键词:
双环开口谐振环对
平面左手超材料
3维磁超材料 相似文献
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Haixin Zhou Keqian Zhang Jianguo Xiao 《International Journal of Infrared and Millimeter Waves》1999,20(8):1549-1562
Eigenequations for a metal-coated planar chiral dielectric waveguide and a mirror-conjugate planar chiral dielectric waveguide are derived. The eigenequations are given in simple formulations. The results indicate that the perfect conductive (or magnetic) boundary can produce mirror-conjugate of chiral media and the left-handed and right-handed circularly polarized modes couple with each other due to the conductive boundary. The propagation characteristics of a metal-coated planar waveguide with chiral core are presented. An interesting phenomenon is observed that the field distributions vary with respect to the operating wavelength. 相似文献
7.
提出了基于金属结构单元间耦合进行左手材料设计的思想,并建立了理论分析模型.通过合理选择结构单元的结构参数并通过单元之间的耦合,使电谐振等效电路的谐振频率与磁谐振等效电路的谐振频率相等,从而最大限度地实现宽左手频带.加工、制作并测试了基于金属结构单元间耦合的左手材料.实验结果表明,测试样品具有相等的电谐振频率和磁谐振频率,其左手频带的带宽为24 GHz.实验结果与理论分析一致,验证了基于金属结构单元间耦合的左手材料设计思想.
关键词:
左手材料
单元间耦合
等谐振频率
宽频带 相似文献
8.
用磁谐振器和电谐振器组合构成左手材料是设计左手材料的一个重要方法.基于这一设计方法,提出了能够抑制双各向异性的磁谐振器和电谐振器设计原理,即单回路镜像对称设计原理和双(四)回路镜像对称设计原理.根据这两个设计原理,设计了具有双负特性(负介电常数和负磁导率)的新结构,并通过实验仿真验证了结构的双负特性,从而验证了两种设计原理的正确性.所提出的两个设计原理以及新结构对于设计新型左手材料具有重要的实际意义和指导意义.
关键词:
左手材料
单回路镜像对称
双回路镜像对称 相似文献
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The TE/TM polarization conversion characteristics of dielectric grating composed of left-handed materials for the case of
plane wave oblique incidence are carefully investigated by a method which combines the multimode network theory with the rigorous
mode matching method. It is indicated that complete polarization conversion between TE and TM modes can be realized using
left-handed gratings. This can hardly achieve in the conventional right-handed gratings. Comparisons of polarization conversion
properties between right-handed gratings and left-handed gratings are given with physical explanations. This unique merit
of left-handed periodic structure is of important significance for accurate design of new millimeter wave TE/TM polarization
converters. 相似文献
11.
通过设计一定的单元结构, 可以实现超宽带人工电磁材料. 基于蘑菇型金属结构, 提出了一种同时具有左右手通带无缝结合的超宽带双入射型复合媒质材料结构单元. 该结构由嵌入到介质板的两个反向对称的蘑菇型金属结构组成, 能够同时引发电谐振和磁谐振而得到左手通带. 通过利用CST软件仿真、等效电磁参数提取、折射率计算以及建立等效磁谐振电路模型等方法, 分析验证了该结构的双入射特性和左手特性. 仿真结果表明, 在电磁波垂直于介质板和平行于介质板入射两种情况下, 在X波段均表现出左手通带特性, 并具有1 GHz以上的左手带宽. 当电磁波垂直于介质板入射时, 在7.2 GHz-9.3 GHz频段为右手通带, 在9.3 GHz-11 GHz频段为左手通带; 当电磁波平行于介质板入射时, 在7.0 GHz-9.0 GHz频段为右手通带, 在9.0 GHz-10 GHz频段为左手通带. 在两种情况下分别于9.3 GHz与9.0 GHz处得到了零折射率, 从而构造了一种正-零-负复合媒质材料, 实现了具有3 GHz带宽的双入射超宽带平衡结构. 相似文献
12.
At microwave frequencies, hollow metallic waveguides behave in certain aspects as a "one-dimensional plasma." This feature will be advantageously used for simulating the propagation of electromagnetic (EM) waves in left-handed metamaterials provided the hollow waveguide is periodically loaded with split ring resonators. It will be shown that EM transmission in this structure is feasible within a certain frequency band even if the transverse dimensions of the waveguide are much smaller than the associated free-space wavelength. This effect can be qualitatively and quantitatively explained by the left-handed metamaterial theory, thus providing a new experimental validation for such a theory. 相似文献
13.
Yu-guang Zhu Xiong Yang Li-xiang Shen Yan-bin Zhuang 《Journal of Russian Laser Research》2013,34(5):434-440
In order to obtain multi-channels of left–right-handed circular polarizations, we design a structure with coupled magnetic resonators and study its transmission properties using the tight-binding model and the 4×4 transfer matrix method. The incidence of a linearly polarized light can be split into two groups of resonant peaks. One group corresponds left-handed circular polarization and the other group corresponds to right-handed circular polarization. By properly adjusted magnetization, the two group can be merged into one group, in which the channels of left-handed circular polarization and right-handed circular polarization are alternately arranged in the transmission spectrum. Thus, we can obtain the comb-channels of left–right-handed circular polarizations. 相似文献
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提出了基于传输线比拟模型的左手材料微结构设计方法,并对此进行了分析、验证.首先根据已有的具有左右手性质的基本传输线模型,通过类比构建了具有左手性质的新模型,进而通过定性分析传输线网络中的各元件与微结构连续介质构型的形状及尺寸的对应关系,推断出模型中各部分的具体尺寸,从而得到了一个合理的左手材料微结构构型及其对应的传输线比拟模型.对设计的模型进行了实验测试,验证了模型确实具有左手性质.最后,通过数值模拟和实验,研究了微结构的各个尺寸参数对材料出现左手性质的带宽和频段的影响,确定了微结构中对左手性质影响最大的尺寸参数. 相似文献
16.
提出了一种利用电谐振器与磁谐振器集成于一体的单面左手介质结构设计方案, 该方案采用两个十字架型金属结构镜像并列放置在介质基板的同一侧形成一个左手单元, 并将其排列成周期结构. 软件仿真和优化提取了一系列有效电磁参数, 结果表明, 该结构在9.4–16 GHz的频率范围内等效介电常数和等效磁导率同时为负, 其相对带宽达到了52%, 并且单元电长度和损耗都小于同类型的结构. 对该结构进行了加工、制作并通过波导法测试再次证明了其优良左手特性的存在性. 为左手材料的广泛应用打下了基础. 相似文献
17.
左手系材料界面上的非线性TE电磁波 总被引:4,自引:4,他引:0
针对电磁波在非线性左手系材料中的传播性质, 分别研究了左、右手系材料界面以及两左手系材料界面上非线性TE表面波的传播行为讨论了导波的频率特性、色散关系以及群速度随频率的变化规律分析表明,两种界面上的非线性TE表面波均存在频率通带和禁带,且带宽是传播功率的函数揭示了在一定条件下,左、右手系材料界面上既可以支持正向传播的非线性TE表面波,也可以支持反向传播的非线性TE表面波;两左手系材料界面上表面波的传播性质因材料参量的变化差异较大,一定参量条件下,该界面上仅支持反向传播的非线性TE表面波. 相似文献
18.
New double-layered electromagnetic absorbers are presented in this paper. The new absorbers composed of one lossy left-handed
material absorbing layer and one impedance matching layer consisted of lossless right-handed material. It is indicated that
the reflection loss of below −20dB can be obtained in the frequency range 7GHz–13GHz. Power attenuation achieving −50dB of
narrow frequency band electromagnetic absorbers can also be obtained by modulate permittivity of right-handed material. Furthermore,
the thickness of the whole absorbing structure is only 2mm, which is particularly helpful in some practical applications.
The presented results are of reference significance for accurate design of the new electromagnetic absorbers and of practical
prospects for stealth technology. 相似文献
19.
We consider electromagnetic waves guided by slabs of anisotropic resonant magnetic metamaterials in free space and in metal
waveguides. It is shown that wave propagation is possible in a waveguide below cutoff with an insert of such a metamaterial.
The dependence of the dispersion properties of waves on the geometric sizes of the insert and the waveguide are studied. The
obtained results can be used for miniaturization of electrodynamic systems.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 7, pp. 618–625, July 2006. 相似文献
20.
Lin Wu Zhenyu Yang Yongzhi Cheng Rongzhou Gong Ming Zhao Yu Zheng Ji’an Duan Xiuhua Yuan 《Applied Physics A: Materials Science & Processing》2014,116(2):643-648
In this paper, a kind of bi-layered asymmetrical split ring metamaterial was proposed as a circular polarization converter. Simulations and experiments at the microwave regime showed that the proposed structures can achieve the conversions from right-handed circularly polarized electromagnetic waves to left-handed ones and the reversed conversions in the opposite propagating direction. The linear to circular polarization transmission coefficients and the surface currents were investigated to understand the mechanism of the circular polarization conversions. Moreover, we optimized the proposed metamaterials by increasing the distance between the two metal layers. The proposed circular polarization converters have applications in microwave wave plates and metamaterial antennas. 相似文献