空气阻尼对微谐振器品质因子及其传输函数的影响

振动方向平行于衬底的梳状微谐振器的品质因子在高真空下可以高达10⁵以上.常压下,受空气阻尼影响,品质因子跌落到10²左右甚至更小.为了设计时能对谐振器的品质因子有一个较为精确的估计,本文首先利用纳维尔-斯托克斯近似方法和库特近似方法对常压下的横向振动谐振器的阻尼功耗进行了估算.同时谐振器作为电路元件,阻尼等效于电路中的电阻,直接影响器件的传输函数,因此本文又建立了该种谐振器的集总参数网络,研究了阻尼对传输函数影响。其结果对横向振动微谐振器的设计有一定意义.

Influence of Slide Films Damping on Quality Factor and Transfer Function of Laterally-Driven Comb Microresonator

The quality factor (Q) of 10 5 for laterally driven comb-shape micro-resonator can be achieved in vacuum chamber. But, Q could fall off to even much lower than 10 2 when the micro-resonator is exposed in atmosphere. For the sake of getting accurate evaluation of Q for the micro-resonator, the Coutte-type model and Stocks-type model were used to estimate the slide-film damping energy dissipation of micro-resonator.The results reveal that the average discrepancies have been reduced to below 7%.And in electronics, the damping of micro-resonator is equivalent to resistance of circuit, which would influence the electrical transfer function directly. So, a lumped-parameter electrical equivalent circuit is developed.The influence of slide damping on transfer function is then studied. The result is helpful to design micro-resonator to some extent.