Real-time Direct Temperature Estimation of MEMS Resonators Through Indirect Q-factor Measurement

Extensive research have been conducted to improve the characteristics of resonant frequency with temperature variations in silicon resonators for various applications. However, temperature measurement delays due to temperature gradient across the chip make it challenging to improve temperature characteristics. This study proposes, a method of measuring the Q-factor of MEMS resonators in real time and estimating their temperature without any time delays using the measured Q-factor. The proposed real-time indirect Q-factor estimation method was validated based on ring-down Q-factor measurement method, and it is suitability for application in the operating environment of MEMS resonant accelerometers was assessed through acceleration-induced testing and temperature cycling tests. The experimental results on the variation of the resonant frequency with temperature validate an improvement in temperature estimation using the proposed method. The proposed method reduced temperature hysteresis characteristics from 3.2019Hz to 1.122Hz, achieving a 65% improvement.