Temperature-frequency drift suppression via electrostatic stiffness softening in MEMS resonator with weakened duffing nonlinearity

摘要

This paper reports a silicon micromechanical resonator with Duffing nonlinearity weakened and temperature-frequency drift suppressed by electrostatic tuning. By operating the resonator in an elastic mode via semicircular beams, we can weaken the instability of amplitude-frequency dependence to linearize the behavior of electrostatic stiffness softening. The mutual independence of linear frequency modulation by temperature and DC bias is theoretically modelled and experimentally verified. Based on this finding, an active temperature compensation model by slightly regulating DC bias voltage is established. The experimental results show that the resonator has a slight Duffing nonlinearity and a maximum frequency inaccuracy of only 66 ppm during a temperature ramp across a testing span of 70 degrees C. This active technique does not need additional power consumption and is generic to a variety of electrostatic resonators.