A gimbal-type torsional z-axis micromachined gyroscope with a non-resonant
actuation scheme measures angular rate of an object with respect to the
axis normal to the substrate plane (the z-axis). A 2 degrees-of-freedom
(2-DOF) drive-mode oscillator is comprised of a sensing plate suspended
inside two gimbals. By utilizing dynamic amplification of torsional
oscillations in the drive-mode instead of resonance, large oscillation
amplitudes of the sensing element is achieved with small actuation
amplitudes, providing improved linearity and stability despite
parallel-plate actuation. The device operates at resonance in the sense
direction for improved sensitivity, while the drive direction amplitude
is inherently constant within the same frequency band.