基于腔结构的射频微机械谐振元件的设计

Design of RF MEMS resonator components based on cavity structure

对圆柱形复合腔结构微机械谐振元件进行了设计研究,提出了一种基于柱形腔结构的微机械复合谐振元件的设计方法,并对其结构及特性进行了研究。建立了复合腔结构的电磁场数学方程,腔体基于体微机械微细加工技术实现工艺设计,最后对该元件进行了仿真分析。TM010模式下,谐振腔谐振频率为24.313299GHz,Q值为3529.707890,考虑微带耦合时仿真出复合谐振元件的最佳谐振频率为24.75GHz。仿真实验结果和理论值的平均误差不到1%,两者吻合得很好,说明了该设计的可行性。进一步改变结构参数,可获取不同谐振频率的器件,且可在腔体中填充高介电常数介质来减小器件的谐振频率,克服了以往使用腔体结构在低频段时体积过大等问题。

The structure and performance of a complex cavity Micro-Electro-Mechanical-System resonator are analyzed with its electromagnetism equations established. Its fabrication was realized by built micromachining, and the structure is simulated on computer at the end. A micro machined-cavity resonator was designed with a TM_(010) resonance quality factor of 3 529.707 890 at 24.313 299 GHz. When the micro-strip coupling conditions are considered, the best guess for the highest eigen frequency would be 24.75 GHz, and the average error of theoretical results and simulated results is less than 1%. The simulation results are in very good agreement with the theoretical value and this testifies the feasibility of the design. The structure parameters of the component are further varied, to obtain multivarious frequency components. The resonance frequency of a component is reduced by filling high permittivity medium, and this makes it possible to keep the design of a component compact at low frequency even.