A micromachined z-axis rate gyroscope with multidirectional drive-mode has
an increased drive-mode bandwidth for relaxing mode-matching requirement
in which the drive and sense modes are completely decoupled. By utilizing
multiple drive-mode oscillators with incrementally spaced resonance
frequencies, wide-bandwidth response is achieved in the drive-mode,
leading to reduced sensitivity to structural and thermal parameter
fluctuations. Quadrature error and zero-rate-output are also minimized,
due to the enhanced decoupling of multi-directional linear drive-mode and
the torsional sense-mode. Bulk-micromachined prototypes have been
fabricated in a one-mask SOI-based process, and is experimentally
characterized.