A MICROMACHINED VIBRATING GYROSCOPE

A vibrating microgyroscope with a thin polysilicon resonator fabricate d by silicon surface micromachining is described. The 400 mu m x 800 m u m resonator is driven in a lateral direction by electrostatic force, and the angular rate is detected as the capacitance change between th e resonator and its substrate. Mechanical e-factors for the driving mo de and the detecting mode of the polysilicon resonator are 2800 and 16 000, respectively, at pressures below 0.1 Pa. Methods are presented fo r modifying the difference between the resonance frequencies of the dr iving and detecting modes. The test device shows a noise-equivalent ra te of 2 degrees s(-1).