Analysis of phase drift based on uncertainty analysis in electro-thermal excited MEMS resonant sensor

Vibration model of double-clamped resonant beam for a MEMS resonant sensor driven by electro-thermal excitation is established. Thermal phase drift caused by electro-thermal excitation and output frequency error of phase locked loop (PLL) caused by thermal phase shift are analyzed. The effects of uncertainty distributions of structure size and excitation voltage due to fabricating or control errors on thermal phase drift and output frequency error of PLL are studied. The sample-based stochastic model is established to investigate the influence of different uncertain structure sizes and excitation parameters on thermal phase drift and output frequency error of PLL; the results are compared with that of experiment on different sensor samples. The results reveal the different influences of these parameters, which can be used as reference for design and optimization of the structure sizes and excitation parameters.