等离子体微带开关特性

Characteristic of plasma-based microstrip switch

提出一种基于微放电等离子体的微带开关。它是以"时变等离子体"取代微带线射频微机电开关的"金属悬臂",利用等离子体的导体或介质特性使电磁波沿其表面进行传输或截止,从而实现微带线上电磁波传输的动态控制。等离子体微带开关的基本结构包括用以隔断电磁波的微带间隙和产生片状等离子体的放电装置。放电产生时,电磁波因等离子体导体性通过开关,形成"开"状态;放电停止后,电磁波被微带间隙反射,形成"关"状态。利用CST软件仿真研究了等离子体开关特性,结果表明:这种开关的带宽由等离子体密度决定,隔离度由间隙决定,而工作插损与等离子体密度和电子碰撞频率有关。等离子体位形(宽度、厚度等)对于开关性能也非常重要。

A novel microstrip switch was developed based on micro-discharge plasma.The plasma switch is a dynamic device of microwave component to control the propagation of electromagnetic wave on the microstripline structure,which has a similar structure as RF MEMS switch but replacing its connecting anchor by using time-varying plasma.A basic structure of plasma switch contains a microstrip line with a small gap which is able to block electromagnetic wave and a discharge configuration which can generate a sheet-like plasma.When the discharge is turned on,the electromagnetic wave will transmit through the gap with the help of the conductive plasma,resulting in the ON state.When the discharge is extinguished,the electromagnetic wave energy will be reflected by the stripline gap,realizing the OFF state.The results from CST simulations show that the bandwidth of this plasma switch is determined by the plasma density,the isolation is determined by the microstrip structure and the gap itself,and the insertion loss is related to the plasma density and the electron-molecule collision frequency.The plasma structure（thickness,width,etc） is also important for the function of the plasma switch.