空间大功率微波器件抑制微放电表面处理技术

Abstract: Mulitipactor has become a big challenge for the miniaturization and high-power development of microwave components in space application. In the project，we will develop a novel multipactor-suppression technique of the high power microwave components by micro- and nano- structured secondary electron trapping surface together with ultra-thin passivation coating. To achieve the secondary electron yield (SEY) and multipactor suppression, the project proposes two different kinds of surface treatment routes: the fabrication of micro- and nano- porous structure and the functional protection coating on the surface. In consideration of the aerospace requirement, low insertion loss and anti-oxidation stability are adopted to optimize the surface treatment route. The characteristics of the secondary electron emission (SEE) based on the regular and irregular surface are investigated though the Monte-Carlo simulation of secondary electron. Combined with the theory analysis and the experiment results, an accurate phenomenological model of the SEE character is to be obtained. The multipactor numerical simulation and multipactor experiment are carried out based on the microwave components such as the microwave switch in frequency of L, C, S and Ku. The project shows both of great scientific interest and engineering application value in the multipactor research field. And it can improve the capacity of basic research and independent innovation in high-power space microwave technology.

微放电效应是制约空间微波器件向大功率、小型化发展的瓶颈问题。项目系统研究空间大功率微波器件的微纳陷阱结构制造和表面钝化处理技术，获得下一代空间大功率微波器件的微放电抑制新途径。开展微纳尺度二次电子陷阱结构的可控制备和表面纳米薄层钝化方法研究，通过多约束条件下的优化过程形成具有低表面SEY且同时满足低插损电性能和抗环境氧化表面稳定性的表面处理技术；系统研究规则和非规则陷阱结构的表面二次电子发射特性实验规律，通过表面微观织构上二次电子漫反射模拟方法研究二次电子抑制机理和规律，理论和实验相结合获得表面处理后准确的二次电子发射统计特性唯像数学模型；开展微波开关等器件的二次电子倍增机制和抑制规律的微放电数值仿真，并在L、C、S、Ku等多个波段实现对微放电抑制实验验证。该项目对大功率微波器件微放电效应问题研究具有重要的科学意义和工程应用价值，能够显著提高大功率微波技术领域的基础研究水平和自主创新能力。

微放电效应是制约空间微波器件向大功率、小型化发展的瓶颈问题。研究适用于空间大功率微波器件的表面微纳陷阱结构制备方法和表面钝化处理技术，能够大幅提高微波器件微放电阈值，这对于提高空间大功率微波器件的抗微放电能力、延长器件寿命有重要意义。. 通过项目研究，课题组设计了多种能够抑制二次电子产额的微纳形貌结构和表面镀层，得到了多种能够剧烈抑制空间金属表面二次电子产额的方法，且获得的各类表面对于二次电子产额峰值的抑制程度至少在30%以上。关于低电子产额表面的研究结果表明：经过长时间的放置，各类表面会产生不同程度的吸附、沾污和氧化行为，表面的电子产额抑制特性也会有所劣化；应用低电子产额表面处理工艺的微波部件其微放电性能得到有效改善，其中，应用了陷阱结构工艺处理的铁氧体环行器，其微放电阈值提高8倍以上。