To reduce the frequency split of the drive mode and the sense mode of a vibrating ring gyroscope to improve the performance of the gyroscope

a novel symmetrical structure with electromagnetic driving and detection is proposed in this paper. The Micro-machined Vibrating Ring Gyroscope (MVRG) is fabricated in centro-symmetric and mirror-symmetric micro structures by MEMS bulk silicon processing with (100) oriented single-crystal silicon

which is conductive to reducing the frequency split. A closed-loop control circuit consisting of a low noise front-end amplifier

a phase shifter and a Variable Gain Amplifier (VGA) is developed to track the drive mode resonant frequency and to stabilize the vibration amplitude of the drive mode. The test results show that the frequency split of drive mode and the sense mode is about 0.27 Hz

which means the frequencies have been matched well. The sensitivity of this gyroscope is 8.9 mV/(°/s)

the resolution is 0.05°/s and nonlinearity is about 0.23% in the rotation rate ranges of ±200 °/s.