【作者】 刘天胜；

【导师】 袁斌；

【作者基本信息】 上海交通大学 ， 电磁场与微波技术， 2008， 硕士

【摘要】 随着现代通信技术的发展,人们对微波器件的性能提出了越来越高的要求。由于等离子体具有快速可调等优点,使得结合等离子体技术的新型微波器件研究成为近年来学术界的一大热点。本文以等离子体的基本电磁特性为基础,对非磁化冷等离子体的频选特性以及在抑制微波滤波器寄生通带方面的应用进行了详细的研究。具体而言,首先通过推导介质-等离子体交界面的反射系数和透射系数,证实了等离子体具有高通特性以及对于低于等离子体频率的入射频率而言具有似金属性,接着研究了“三明治”等离子体分层结构的带通特性。然后着重研究了一种利用非磁化冷等离子体的频选特性抑制微波滤波器寄生通带的新方法。利用此方法,设计了一个在微波波导滤波器输入输出耦合结构的单端增加等离子体,用于抑制3ω0处寄生通带的算例。通过该算例仿真发现,其寄生通带可被抑制在? 20dB以下,且有进一步优化的空间。此外,还研究了等离子体器件的可调性、制作方法及相关实验设计。最后,开发了一个等离子体微波器件分布式仿真平台,用来辅助一些单机版电磁仿真软件处理大批量仿真计算。更多还原

【Abstract】 The development of modern communication has driven a higher demanding on microwave devices. Novel microwave devices with plasma technologies become new research hotspots due to the fast tunablity of the plasma.In this paper, based on the basic electromagnetic characteristics of plasma, the frequency selectivity of the non-magnetized plasma and its application in inhibiting parasitic pass-band of microwave filters are studied carefully. Concretely, the first work is to analyze and approve the high-pass property of the plasma, metal-like characteristic to the frequency which is lower than plasma frequency, and the band-pass property of layered structure called ’sandwich’ filled with plasma through the research of reflection and transmission coefficients. And then, based on the frequency selectivity of the non-magnetized plasma, a new method for inhibiting parasitic pass-band of microwave waveguide filters is put forward. Using this method, this paper designs a case of microwave waveguide filter in which the plasma layer is putted in one end of input and output coupling structure of the filter in order to inhibit parasitic pass-band of frequency tripling. And its simulation results show that this method can inhibit parasitic pass-band to lower than -20dB and this result can be further optimized. In addition, the filter’s tunablity, the manufacture scheme, plasma generating and measurement experimental methods of plasma microwave devices are studied. Finally, a distributed simulation platform for designing plasma microwave devices is developed in order to assist some stand-alone simulators in processing batch tasks.更多还原