A micromachined vibrating rate gyroscope with independent beams for the drive and detection modes

We investigated the mechanical coupling between the drive and detection modes of micromachined vibrating rate gyroscopes, and designed and fabricated a gyroscope with a new structure to reduce the coupling. The coupling of the oscillator was measured using a new measurement system with a two-dimensional laser displacement meter. The oscillations were found to have an elliptical motion due to the coupling. When the frequency mismatch was reduced by means of electrostatic frequency tuning with a DC bias voltage, the coupling increased. The new structure, which has independent beams for the drive and detection modes, exhibited weaker coupling; and the resolution was 0.07 deg/sec at a bandwidth of 10 Hz.