MEMS Array Structures for Gyroscopes with High Resonant Frequencies

A vibratory gyroscope apparatus, comprising:

• a mechanical resonator having a first mode of vibration in a first axis of motion and an associated first natural frequency, and a second mode of vibration in a second axis of motion having an associated second natural frequency, wherein angular rate of motion of the vibratory gyroscope apparatus couples energy between said first mode of vibration and said second mode of vibration;
• sensors and actuators for each of the first mode of vibration and the second mode of vibration for, respectively, transduction of a mechanical vibration into an electrical signal and transduction of an electrical signal into a mechanical vibration;
• drive circuitry connected to the actuators to impart substantially constant, non-zero velocity amplitude vibrations in the first mode of vibration at a first frequency and the second mode of vibration at a second frequency;
• and
• output circuitry connected to the sensors to measure mechanical forces created by the angular rate of motion of the vibratory gyroscope apparatus to either or both of the first mode of vibration or second mode of vibration,
• wherein the mechanical resonator comprises a substrate and a proof mass array positioned in spaced apart relationship above a surface of the substrate and constructed with a plurality of proof mass sub-structures which are each separately connected to the substrate with orthogonally disposed pairs of compliant anchor structures and which are each rigidly connected to one or more adjacent proof mass sub-structures with one or more rigid connector bars so that the plurality of proof mass sub-structures move as a single proof mass array that can operate at resonant frequencies of at least 100 kHz when oscillating in the first mode of vibration and/or second mode of vibration.

A MEMS gyroscope comprising:

• an N×M proof mass array positioned in spaced apart relationship above a surface of a substrate and constructed with a plurality of proof mass sub-structures arranged in an N×M array, where each proof mass sub-structure is separately connected to the substrate with orthogonally disposed pairs of spring suspension structures and where each proof mass sub-structure is rigidly connected to one or more adjacent proof mass sub-structures with one or more connector bars so that the plurality of proof mass sub-structures can operate at resonant frequencies of at least 100 kHz when oscillating in a first axis direction and a second axis direction;
• a first plurality of N drive actuators configured and connected to impart a first oscillating motion to at least part of the N×M proof mass array in the first axis direction;
• a second plurality of M drive actuators configured and connected to impart a second oscillating motion to at least part of the N×M proof mass array in the second axis direction that is orthogonal to the first axis direction, at least one of the first and second axis directions being parallel to the surface of the substrate;
• sensors for transducing oscillating motion of the N×M proof mass array in each of the first and second axis directions into electrical signals;
• and
• output circuitry connected and configured to measure an angular rate of motion of the MEMS gyroscope based on the electrical signals received from the sensors.