【作者】 李洵；

【导师】 胡兵；

【作者基本信息】 华中科技大学 ， 物理电子学， 2007， 硕士

【摘要】 在激光加工领域,射频CO2激光器由于其卓越的性能而得到了广泛的应用,国内相关机构也开展了这方面的研究,但是还没有国产射频CO2激光器投入运用。本文重点对射频CO2激光器射频激励源进行了研究。文章首先介绍了射频CO2激光器发展历史及研究现状,接着介绍了高频击穿理论和射频激励,并介绍了射频CO2激光器的结构和冷却的方法,总结了射频CO2激光器高效运转的因素,这对深刻理解射频激励源的性能要求有着重要意义。然后介绍了元器件高频模型。元器件的特性在高频条件下和低频条件下有很大的差别,不同的类型、相同数值的元件在具体电路中的表现也会有很大差别,如果选择不合理,将会导致实际的激励源和设计的激励源有很大差别,甚至根本就不能工作。同时介绍了印制板材的选择,这也是一个影响激励源性能的重要因素。接着分析了射频激励源的阻抗要求,并给出了测定射频放电阻抗的方法。本文所研究的射频激励源并非50?(或75?)标准工业射频电源,因此为了达到对负载的输出功率要求,必须预先知道激光器射频放电阻抗。最后基于SYNRAD 48J-1激光器,详细介绍了三种激励源的设计方案及相关理论。(1)集中参数多极放大射频激励源(2)运用微带线技术的射频激励源(3)功率振荡器射频激励源在设计过程中,使用了ADS2003C仿真平台,运用了谐波平衡仿真、相位噪声分析等技术。在SYNRAD 48J-1激光器上的实验表明,三种方案都具有可行性,但是从各方面因素考虑,射频激励源应该朝着微带线与功率振荡器相结合的方向发展。更多还原

【Abstract】 The RF-excited CO2 laser is widely applied in laser process for its excellent capability. At meantime, some universities and institutes in China have been taking research into it, but no products have been successfully taking into practice. This thesis is focus on the research of RF-excited source for RF-excited CO2 laser.The trend and the key technique of RF-excited CO2 laser are firstly introduced here, and then the factors relevant to the characteristic of RF-excited CO2 are further discussed. All these elements are significant for understanding the requirements of RF-excited source.The model of passive components and the rule of PCB layout are demonstrated. Although in the same circuit, the characteristics of passive components are quite different when they are in a high frequency condition. So, we have to make an appropriate selection among all the components available.The experimental study on impedance characteristics of the laser at RF discharge excitation is also introduced here. Without this parameter, we can’t carry out the design of RF-excited source.Finally, three different designs of RF-excited source based on the SYNRAD 48J-1 series RF laser have been introduced and exactly analyzed with relevant experiment results. All the designs are aided by ADS2003C, which is a Agilent’s product for RF/MW simulation. The Phase Noise Analysis, Harmonic Balance, and Load-pull simulation skills are utilized during the design.According to the results of experiments on SYRAD 48J-1, there kinds of RF-excited source can work well. But considering many aspects, such as the volume, stability and safety, we should combine microstrip technology with the power oscillator in the design of RF-excited source.更多还原