Micro Hemispherical Resonator Gyroscope With Teeth-Like Tines

Abstract

Micro hemispherical resonator shows great potential for applications in high-performance gyroscopes. This paper introduces micro hemispherical resonator with teeth-like tines along the edge, aiming at improving mechanical sensitivity of the gyroscope and simplifying the mechanical trimming. The optimized glassblowing resonators with substrate thickness of 200 μm and height near 4.5 mm shows high quality factor, large sensitivity, and balanced electrode gaps. The n = 2 wineglass modes operate at 4.3 kHz, achieving quality factor of 1.18 million and as-fabricated frequency split of 17.8 Hz. After mechanical trimming, the frequency split is reduced below 70 mHz. The vacuum-packaged micro hemispherical resonator gyroscope (mHRG) operating in force-rebalance mode exhibits full-scale range of ±200 deg/sec and bias instability of 0.133 deg/h at room temperature without compensation, indicating that the performance of the gyroscope is limited by the readout electronics. Further improvement is in progress to achieve navigation-grade performance with rate-integrating operation.