INVESTIGATION OF THE MEASURED QUALITY FACTOR VERSUS POLARIZATION VOLTAGE OF A MULTIPLE-BEAM TUNING-FORK GYROSCOPE

In light of the importance of the mechanical Quality factor (Q) to the ultimate performance of tuning-fork gyroscopes, this paper presents an investigation on the effect of polarization voltage on the Q of a multiple-beam tuning-fork gyroscope. An experimental study is conducted to quantify the relation of the measured Q of the gyroscope to polarization voltage. The two loss mechanisms, thermoelastic damping and anchor loss, in the device are analyzed to identify the reason behind the Q drop with polarization voltage. Using a numerical model of thermoelastic damping built upon thermal-energy method, polarization voltage is found to have a negligible effect on the Q of the gyroscope. Due to the asymmetry of the fabricated devices resulting from fabrication variations, anchor loss is identified as the cause of the Q drop with polarization voltage and an analytical model of anchor loss is further proposed to take polarization voltage into account.