【作者】 程芝峰；

【导师】 韩建伟； 徐跃民；

【作者基本信息】 中国科学院研究生院（空间科学与应用研究中心） ， 空间物理学， 2010， 博士

【摘要】 等离子体反射面天线是等离子体天线技术中一种新的应用方向,它能以简便的方式实现波束的快速扫描。由等离子体反射面天线构成的雷达系统,是一种多功能、高性能的新型电扫描雷达系统。等离子体微波反射面是等离子体反射面天线技术的基础,它决定了反射面天线的性能参数及工作模式。本文从等离子体片的基本参数和微波在等离子体片中传播的特性这两个角度出发,对等离子体微波反射面的性能特点进行了较为全面的研究。主要工作及成果有:(1)对等离子体微波反射面的实现方法进行了研究,完成了包括介质真空腔体、亥姆霍兹线圈、大尺度线形空心阴极放电电极、真空过渡连接器件、放电电路、测试电路等等离子体放电系统主体部件的设计;完成了等离子体源的基本方案;完成了用于产生等离子体微波反射面的磁约束线形空心阴极放电演示系统的组装调试,使其能稳定地生成大尺度均匀高密度的等离子体片,为等离子体微波反射面的研究提供了实验平台。(2)完成了适用于等离子体微波反射面演示系统等离子体特征参数诊断的静电探针研制,利用其进行了等离子体参数的测量,并以实验数据对磁约束线形空心阴极放电的相关机制进行了研究。通过微波与光谱手段对等离子体特征参数进行诊断与分析,验证了静电探针测量结果的可靠性。(3)采用分层计算法对电磁波在等离子体中的一般性传播特点进行分析研究,给出了不同的参数条件下电磁波在无限大等离子体片中所发生的反射、透射及相位的变化特征。(4)分别采用实验手段和时域有限差分(FDTD)仿真手段对天线发射的微波波束在等离子体微波反射面上的反射性能进行了测试与研究,研究表明等离子体片的密度、厚度及偏转角度对波束反射有明显的影响,得到了等离子体微波反射面在一定频段条件下的理想工作参数。(5)结合等离子体微波反射面的反射特性,给出了等离子体反射面天线系统的性能参数特点;对等离子体反射面天线原理样机的辐射方向图进行了初步的测试,为等离了体反射面天线的可行性提供了实验依据。更多还原

【Abstract】 Plasma reflector antenna technology is a new application in plasma antenna, which provides a simple way for microwave beam steering. The radar with the unique advantages of plasma reflector antenna is a new, multi-functional, high-performance electronic scanning radar system. The plasma microwave reflector is the basic component of plasma reflector antenna technology, which decides the performance parameters and operation mode of the antenna. In this paper, the features of the plasma microwave reflector are studied from two directions: the basic parameters of the plasma sheet and microwave transmission characteristics in the plasma sheet. The main work and outcomes include:(1) The research on the generation method of plasma microwave refletor is done. It includes the design of the main components of the plasma discharge system, like the dielectric vacuum chamber, Helmholtz coils, large-scale linear hollow cathode discharge electrodes, vacuum adapters, discharge circuits, and the test circuits. Also, the basic disign of the plasma excitation power is completed. Furthermore, the assembly and debugging of the magnetic constrained linear hollow cathode discharge demonstration device is completed, which is used to produce the plasma microwave reflector. So that, it can stably generate large-scale, high-density uniform plasma sheet, providing an experimental platform for the research of plasma microwave reflector.(2) The electrostatic probe fit for the diagnostic of the plasma characteristic parameters of the plasma microwave reflector demonstration device is completed. Based on this, the measurement of plasma parameters is carried out, and the relevant mechanisms of the magnetic confined linear hollow cathode discharge are studied. The plasma characteristics parameters are also diagnosed and analysed through the microwave method and the spectral method, which verify the reliability of the measured results get from electrostatic probe.(3) The general propagation characteristics of electromagnetic wave in plasma is analysed through the sequential stratification method. Also the characteristics of reflection, transmission and phase change of electromagnetic wave in the infinite area plasma under different parameters are given.(4) The reflection properties of microwave beam in plasma microwave reflector are tested and studied by means of experiment and FDTD (finite difference time domain). Studies show that the plasma’s density, thickness and the deflection angle significantly affect the reflected microwave beam. Also, ideal operating parameters of plasma microwave reflector under certain frequencies are gained.(5) The performance parameters of plasma reflector antenna are given out with the reflection characteristics of the plasma microwave reflector. The radiation patterns of the plasma reflector antenna prototype are tested, which provide the experimental evidence for the feasibility of plasma reflector antenna.更多还原