相位非连续性人工电磁表面的研究
毕业论文关键词 人工电磁表面 P-B 相位 旋转角 变容二极管Title Research on the metasurface with discontinuous phaseAbstractManipulating the propagation of electromagnetic wave is one of the traditionalsubject researches of electromagnetism. Conventional optical lens andelectromagnetic control devices mainly use accumulated spatial phase along thetravel path for electromagnetic wave manipulation, while the presence ofmetasurface enables the manipulation within subwavelength size. We firstdemonstrate the relation between polarization transformation and phase change withthe theories of Jones matrix and Poincare sphere. Then, we design a reflectiveunit array structure with rotation axis of different angles, which complementswith the transmission mode, to manually modulate the phase of reflective crosspolarization wave. Besides, we add electronic control component, varactor， tothe unit cell to manipulate the wavefront with the high reflection coefficientand analysis the metasurface with transmittion line model. Since this two typesof metasurface both have the advantages of high efficiency and the wide phasemanipulating range, they can be applied to many fields, such as beam control,refection antenna, phase shifter,etc.
Keywords metasurface P-B phase rotation angle varactor
目次
1绪论1
1.1引言1
1.2课题背景1
1.4本课题的研究内容和意义2
2突变相位的理论分析4
2.1引言4
2.2琼斯矩阵分析突变相位4
2.3庞加莱球表示P-B相位6
2.4交叉极化波转化效率的理论极限7
2.5小结10
3相位突变人工电磁表面研究11
3.1引言11
3.2透射型相位突变单元结构11
3.3反射型相位突变单元结构13
3.4小结17
4电控可调人工电磁表面研究19
4.1引言19
4.2相位调控的实现19
4.3电控可调人工电磁表面的设计21
4.4小结35
结论36
致谢37
参考文献38
1 绪论1.1 引言对电磁波相位的调控一直电磁波专业很重要的课题之一。传统的器件主要是利用累积空间相位来实现电磁波波前的控制，而人工电磁表面作为一种新型的人工构造材料，主要是通过在二维平面内排布具有带有一定周期特征的单元结构，形成非均匀的分界表面，从而引入突变相位。哈佛大学研究小组首先提出了相位非连续人工电磁表面，实现了对透射场中交叉极化的相位和幅值调控[1,2]。在此基础上，基于相位非连续人工电磁表面的电磁波新型调控器件被广泛研究。本课题将在对原有透射型相位非连续人工电磁表面进行改进的基础上，进一步对电控相位可调人工电磁表面单元结构的设计和应用方面进行研究[3-7]。通过对单元结构引入电控元件——变容二极管，来实现对电磁波传播状态的高效人工调控。