为了研究电容式MEMS微波功率传感器悬臂梁的非线性运动, 建立了MEMS悬臂梁在空间域上的弯曲特性模型, 综合考虑静电力、轴向应力以及残余应力对悬臂梁非线性运动的影响, 求解得到动力学微分方程。在此基础上研究在不同杨氏模量、驱动电压和残余应力下悬臂梁的弯曲特性, 解析得到对应的悬臂梁弯曲特性曲线与轴向应力曲线。使用有限元分析软件ANSYS对不同驱动电压下的悬臂梁下拉位移进行仿真, 并对仿真结果与解析结果进行比较。结果表明, 在驱动电压从10 V到20 V的变化过程中, 仿真结果与模型解析结果具有一致的趋势, 两者间的最大误差仅有8.81%。对电容式MEMS微波功率传感器的悬臂梁弯曲特性的研究具有一定的参考价值和指导意义。

In order to study the nonlinear motion of the cantilever beam of capacitive MEMS microwave power sensor, the bending characteristic model of the MEMS cantilever beam in space domain was established. Considering the effects of electrostatic force, axial stress and residual stress on the nonlinear motion of the cantilever beam, a dynamic differential equation was obtained. On this basis, the bending characteristics of the cantilever beam under different Young's modulus, driving voltage and residual stress were studied. And the corresponding bending characteristic curve and axial stress curve of cantilever beam were obtained. Meanwhile, the finite element analysis software ANSYS was used to simulate the pull-down displacement of cantilever beam with different driving voltages, and the simulation results were compared with the analytical results. The results show that when the driving voltage changes from 10 V to 20 V, the simulation results are consistent with the model analysis results, and the maximum error is only 8.81%. Therefore, this work has a certain reference value and guiding significance for the research of cantilever bending characteristics of capacitive MEMS microwave power sensor.