A low-cost high yield surface micromachined gyroscope ispresented with a decoupled drive and sense proof mass. A dualanchor approach is described using folded beam springs and atorsion post to significantly reduce the drive proof mass out ofplane deflection while maintaining a comparatively low rotationalmechanical restoring force. The Z-axis (vertical) proof masssuspension spring constant was increased from 7.86 [N/m] to251[kN/m] with the addition of the central torsion post. Verticalstiction was eliminated from the design using the dual anchorscheme for the proof mass and a triply clamped beam approach forthe fixed electrostatic drive/sense beams. The increase in the Zaxisspring constant of the fixed triply clamped beams is greaterthan 128X as compared to singly clamped cantilever beams ofequal length. In addition, a differential capacitance measurementscheme is presented which rejects undesired proof mass linearacceleration error at the sensor. The sense mode resonantfrequency was measured at 44.96 [kHz] with a quality factor Q of225 in a 3 mtorr ambient. Angular rate resolution was measured at3.8 [deg/s] in a 20 [Hz] bandwidth.
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