返回
类型 基础研究 预答辩日期 2018-04-04
开始(开题)日期 2015-07-03 论文结束日期 2018-01-17
地点 李文正楼北614 论文选题来源 973、863项目     论文字数 5 (万字)
题目 基于超材料与超表面的新型天线研究
主题词 人工电磁材料,天线,透镜,低剖面,可调
摘要 人工电磁材料是由一系列人工电磁单元按周期或非周期排列成的材料,可以在宏观上表现出一些奇异的电磁特性。人工电磁材料对电磁波有很强大的调控能力,可以比较自由的控制电磁波传播的幅度、相位和极化方向等电磁特性,因而受到了人们很大的关注。经过这十几年多年突飞猛进的发展,人工电磁材料的研究已经有了很大的进展,无论是理论上还是工程上都取得了很重大的成果。目前,人工电磁材料本身的研究上,基于各种形式的可调控人工电磁材料是一个研究的热点课题。而在工程应用上,基于人工电磁材料的天线的设计一直是微波段的人工电磁材料最重要的应用方向。本文从这两个方面入手主要进行了如下内容的研究: 设计了工作在37.5GHz的渐变折射率透镜天线。为了减小在高频工作时,因为工艺限制引入的折射率的取值限制,可以在渐变折射率透镜延电磁波传播的方向上采用两个单元组合排列的方式实现折射率的自由取值。 设计了辐射口面上相位分布和幅度分布都均匀的透镜天线。通过在天线内插入金属结构,可以使天线口面上电磁波的幅度分布变成混合模式,实现近似均匀的分布。而渐变折射率透镜可以使天线口面上电磁波的相位分布近似均匀。试验中,通过这两种方法设计的高增益天线可以在14.25GHz实现90$\%$以上的口面效率。 设计了基于宽带高阻抗表面的低剖面天线。通过将工作在不同频率的两个高阻抗单元组合排列,可以在更宽的带宽内展现出高阻抗的特性。基于这个宽带高阻抗表面设计的低剖面天线可以在较宽的频带内实现反射系数低于-10dB的指标。 设计了基于宽带极化转换阵列的低剖面天线。因为反射式线性极化转换器的入射波和反射波互不干涉,所以基于极化转换阵列的低剖面天线拥有更宽的主瓣宽度。与基于高阻抗表面的低剖面天线相比,这个天线具有更好的远场稳定性。在较宽的带宽内,这个天线的远场不会出现栅板,而且可以保证z方向上的增益。 利用电压调控的二极管设计了散射波的极化方向和散射方向可以同时调控的有源人工电磁材料。通过设计合适的结构,可以使人工电磁材料在临近的频段内拥有不同的功能。再利用二极管在不同状态时对人工电磁单元不同的影响,可以使人工电磁单元在同一频段内实现不同的功能。
英文题目 Novel Antennnas Based on Metamaterials and Metasurface
英文主题词 Metamaterials,Antenna, Lens, Low-profile,Tunable
英文摘要 Metamaterials are periodically or aperiodic materials which are composed of subwavelength structures. These materials can show some special electromagnetic properties at the macro level, so it attracts more and more attentions in recent years. With the rapid development in the past nearly 20 years, great progress has been made in the field of metamaterials in both theory and engineering. In this thesis, we will focus on designing antennas based on metamaterials and tunable metamaterials. The main contents and contributions of the thesis are summarized as follows: A high gain antenna is designed at 37.5GHz, using a gradient index lens. To decrease the error caused by the restrictions of the process, the lens is composed of two kinds of metamaterials units in the direction of the propagation of the electromagnetic wave. The two combined units can realize more kinds of refractive index values. A new approach is proposed to design high gain and high efficiency horn antenna with even amplitude and phase distributions. To realize even amplitude, a sheet metal is inserted into the horn antenna. And a gradient index lens is located at the aperture of the antenna to correct the phase error. Full-wave simulation and experiment results prove that the antenna can possess high gain from 14GHz to 15GHz. A wideband low-profile antenna is designed, using a wideband high impedance surface. The high impedance surface is composed of two kinds of unit cells which operate in different frequency bands. The surface can decrease profile of a patch antenna, and realize wide impedance match bandwidth. A wideband low-profile antenna is designed, using a wideband linearly polarization rotator surface. Comparing to the low-profile antenna based on high impedance surface, this antenna can realize wider beam width. So this antenna possess better far-field stability which means that its radiation patterns is difficult to generate grating lobes and can maintain high gain along $z$ axis. A new approach is presented to simultaneously controll the polarization and scattering direction of an electromagnetic wave. By designing suitable structures, the metamaterials can have different functions in adjacent frequency bands. Moreover, voltage controlled diode can affect the equivalent circuit of the metamaterials. So the metamaterials can realize different functions in one frequency, when we change the state of the voltage controlled diode.
学术讨论
主办单位时间地点报告人报告主题
东南大学 2013.10 李文正楼北614 陶醉 Generation of Diffraction-free beams using GRIN Lens
东南大学 2013.10 李文正楼北614 蔡本根 Holographic Metasurface/SPP and Leaky-wave Antenna
东南大学 2014.04 李文正楼北614 蔡本根 Metasurface,A Brief Review
东南大学 2014.11 李文正楼北614 陶醉 Tunable Metamaterial
东南大学 2015.11 李文正楼北614 陶醉 极划转换器的研究
东南大学 2017.01 李文正楼北614 陶醉 可调超材料和可编程超材料
东南大学 2014.08 李文正楼北614 Prof.DouglasH. Weiner Metasurface and MTM-Enabled EM/Optical Devices
东南大学 2014.12 李文正楼北614 Prof.Cheng-Wei Qiu Some Recent Development in Engineering Light-matter Interaction
     
学术会议
会议名称时间地点本人报告本人报告题目
The Electromagnetics Academy Office 2014.08 广州 High Gain and High Efficiency Antenna
Metamorphose 2016.09 Cjamoa. Crete. Greece Low Profile Antenna based on Lossy AMC
     
代表作
论文名称
Reconfigurableconversions of reflection, transmission, and polarizationstatesusingactivemetasurface
A Millimeter-wave System of Antenna Array and Metamaterial Lens
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
冯一军 正高 教授 博导 南京大学
金飚兵 正高 教授 博导 南京大学
程强 正高 研究员 博导 东南大学
蒋卫祥 正高 研究员 博导 东南大学
马慧锋 正高 研究员 博导 东南大学
      
答辩秘书信息
姓名职称工作单位备注
汤文轩 副高 副教授 东南大学