Suppression of spurious signals in thermal MEMS gyroscope

This paper proposes a way of suppressing the confounding effect of acceleration and gravity on the measurement of rotation by the thermal MEMS (Micro-Electro-Mechanical Systems) gyroscope [1]. Gravity, like acceleration, induces convection currents within the device, and the position of these convection currents changes as the two heaters within the device are alternately switched on and off. This creates an alternating signal in phase with the heater switching frequency which can be mistaken for a rotation signal. We suggest that using a smaller gyro with shorter heater switching frequency can reduce this spurious signal. In order to evaluate the new design a mathematical model has been constructed using the COMSOL CFD package. The predicted signal to noise ratio is simulated for gyros with smaller dimensions and higher switching frequencies.