Simulation of characteristic of comb-gimbal micromachined gyroscope

A novel micromachined comb-gimbal gyroscope is presented, which is excited by electrostatic forces and its Coriolis acceleration induced torsional motion is read out capacitively. Since electrostatic comb driving and DRIE (deep reactive ion etching) technology are adopted, the large driving amplitude and higher sensitivity of the gyroscope can be achieved. Driving mode and sensing mode working in different planes may prevent mechanical coupling. Characteristic analysis results obtained from simulation show that when the driving mode frequency equals the sensing mode frequency, the gyroscope may achieve maximal sensitivity. Then according to the matching of the driving mode frequency and detection mode frequency, the structure dimensions of the gyroscope are optimized using the finite element method (FEM). Finally, an equivalent circuit model of the gyroscope is derived, which is available for detection oscillating properties analysis and also enables the simulation of the sensor with the interfacing electronics.