Robust compensation of a force-balanced high-Q gyroscope

Force feedback has been widely used in low-Q sensors to improve bandwidth, drift, and other sensor characteristics, but its use in high-Q vacuum packaged gyroscopes for similar benefits has been hindered by closed-loop instability caused by the highly under-damped higher-order resonances of the sensor. This paper presents a compensation technique that uses positive feedback to overcome this stability challenge. The technique has been experimentally verified in a SigmaDelta closed-loop readout interface with a vacuum-packaged vibratory-rate gyroscope.