【作者】 林桦；

【导师】 袁斌；

【作者基本信息】 上海交通大学 ， 电磁场与微波技术， 2007， 硕士

【摘要】 滤波器是无线电技术中众多设计问题的中心,现代通讯技术的发展对滤波器提出了许多新的、特殊要求,如低耦合宽带滤波、快速可调及大功率容量等。与此同时,等离子体微波器件以其体积小、重量轻、功率高等优点成为研究的热点。本文以现代微波滤波器设计理论为基础,结合等离子体的基本电磁性质,对三明治结构非磁化等离子体矩形波导滤波器进行了详细的理论分析与仿真计算。首先分析了等离子体滤波器中电磁场模式的分布,计算得到了该结构等离子体滤波器的传输系数,证实了在等离子体频率以下完全传输点的存在。通过计算电场的模值,确定滤波器结构中存在谐振现象。进一步通过引入等效PEC面与等效微波谐振腔的概念,分析了谐振现象与滤波特性之间的关系,得到了滤波器中心频率与滤波器结构参数的关系式与中心频率的计算方法。在理论分析的基础上,有效地利用了电磁仿真软件,进行了大量的仿真计算,验证了提出理论的正确性,并仿真设计了多款S、C波段等离子体滤波器。以一阶等离子体滤波单元为研究对象,对等离子体滤波器的电可调性能进行了深入分析,得到了一系列有价值的结论。最后结合实验室现有条件,初步制定了等离子体基础构件的实验方案,设计定制了实验中所需的真空系统与光谱分析系统,完成了等离子体实验的前期准备。更多还原

【Abstract】 Filter is the kernel of many design problems in wireless technology. The development of modern communication technology encounters many new and special requirements such as low-coupled, wideband, high-speed adjustability and large power capacity. Meanwhile, plasma microwave devices become new research interests owing to their small, light and powerful characteristics.This thesis is based on modern microwave filter design theory. Considering the basic electromagnetic characteristics of plasma, the sandwich structure non-magnetized plasma rectangular waveguide filter is investigated in detail theoretically. Firstly, the distribution of electromagnetic field in the plasma filter is studied. The transmission coefficient is calculated and the completely transmission phenomenon under plasma frequency is observed and verified. Resonance of the filter is approved based on power calculation. Furthermore, new concepts of equivalent PEC wall and equivalent microwave resonance cavity are suggested to analyze the resonance phenomenon and filtering effect. The relationship between the filter structure and the filter center frequency is acquired and a method to calculate this center frequency is proposed. Based on theoretical analysis, several plasma filters working in S and C band are designed using electromagnetic simulation software and the electrical tunability of the plasma filter is studied carefully. In the end, An experimental plan to implement plasma filter is suggested. The vacuum system and spectrum analysis system used in the experiment are designed to complete the preparation process of the plan.更多还原