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HuiHui Jing ZhiHua Zhu XueQian Zhang JianQiang Gu Zhen Tian ChunMei Ouyang JiaGuang Han WeiLi Zhang 《中国科学:信息科学(英文版)》2013,56(12):1-18
The quantum phenomena of electromagneticalty induced transparency (EIT) or plasmonic ana- logue of electromagnetically induced transparency (PIT) can be mimicked in the classical resonators, leading to a unique way to explore the coherent coupling mechanism in metamaterial systems. Various metamaterial structures have been proposed to excite and manipulate the PIT effect with flexibility and performance with geometry-controllable, polarizatiomindependent, broadband-transparency and active-modulated characteristics. These in turn promise the fascinating functionalities and applications of the PIT effects, such as slow-light com- ponents, nonlinear devices and high-sensitivity sensors. Here, we present a review on the progress in developing the PIT effect in terahertz metamaterials over the past few years. 相似文献
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针对传统工程用椭圆波束馈源带宽窄、加工难度大等问题,设计了一种新型的椭圆波束馈源,即在角锥喇叭内壁加载超材料层,使得馈源在水平极化和垂直极化两个极化辐射相同椭圆外形的波束。根据阻抗匹配原理,当电磁波水平极化和垂直极化入射时波阻抗的乘积与真空中波阻抗乘积相等时,超材料单元的性能达到最优,将优化后的超材料单元周期排布为超材料层加载到喇叭内壁,即可形成椭圆波束馈源。在Grasp软件中仿真计算了该馈源作为前馈馈源和后馈馈源使用时,反射面天线的电气性能。仿真结果表明:在工作频带10.95GHz-14.5GHz内,基于超材料的椭圆波束馈源实现了良好的极化波束等化,波束宽度比在0.9-1.14之间,驻波小于1.55。前馈照射反射面时,天线效率在65%-75%之间,交叉极化电平低于-30dB;后馈照射反射面时,天线效率在61%-72%之间,交叉极化电平低于-30dB,验证了馈源设计的可行性。 相似文献
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Cloaking objects by transmission line and metamaterial is presented. Simulation results reveal that the bandwidth of this method is increased by embedding the transmission networks in a medium whose refractive index is smaller than unity. The low refractive index medium is realized by embedding thin wires in a host medium. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 22: 663–668, 2012. 相似文献
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基于微带传输线的由特异材料构成的一维光子晶体 总被引:1,自引:1,他引:0
通过左右手复合传输线(CRLH TLs)实现了一维的特异材料(Metamaterials),基于Metamaterials单元构成了光子晶体,并分析、测试了其传输特性.实验结果表明,由特异材料构成的一维光子晶体具有Bragg 带隙和等效的单负带隙.当晶格尺度同比例改变时,等效的单负带隙基本上不发生移动,并且带边分别由零平均介电常数ε-=0和零平均磁导率μ-=0决定.零平均折射率 (zero-n-)带隙和零有效相位(zero-Φeff)带隙可以理解为一种等效的单负带隙.对由Metamaterials构成的一维光子晶体传输特性的研究,有助于Metamaterials在射频/微波电路和仪器中的应用. 相似文献
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The direct design of metamaterial absorbers for the nonplanar surface is cumbersome and inefficient. A new mapping between nonexpandable surfaces and plane structures is proposed, in which the size of geometry on the unit is scaled to avoid the overlap after the mapping. Utilizing this mapping, it is easy to realize the metamaterial absorbers for nonexpandable surfaces, such as the spherical surface, while maintaining or even getting better performance by adopting the genetic algorithm combined with the load‐resistors matrix decomposition method. A prototype has been fabricated by 3D printing technology to precisely locate the units on the spherical crown. The simulation and experimental results show that the designed structure has broadband absorbing bandwidth in the 2.7 to 8.2 GHz for 10 dB radar cross‐section reduction under the normal incidence. This prototype also has good polarization and incident angle stability. 相似文献
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Metamaterials are assemblies of metallic and/or dielectric materials with properties that are not readily found in naturally existing materials. Hence, metamaterial structures are commonly loaded on/near the patch, embedded in the substrate, loaded/etched from the ground plane or placed as a superstrate layer for enhancing bandwidth and gain, and size miniaturization of conventional patch antennas. The demand for wide bandwidth, high gain, and compact antennas is highly contemplated in recent wireless communication research studies. Despite their lightweight, ease of fabrication, low profile, and simplicity for integration, patch antennas have performance limitations as result of their narrow bandwidth, lower gain, larger size, and lower power handling capacity. To address these problems, metamaterial‐based antennas have gained massive interest. There exist inadequate literatures about review of current state of extensive study reports on metamaterial application for patch antenna performance enhancement. Thus, this paper has reviewed and discussed latest research works on metamaterial applications for performance enhancement of planar patch antennas. 相似文献
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