Abstract:Aiming at the difficulty of symmetrical manufacturing of micro-hemispherical gyroscopes, this paper proposes a polysilicon hemispherical resonator structure with self-aligned spherical electrodes, which realizes an integrated molding process with the same curvature of the electrode and the resonator. Therefore, the symmetry of the resonator and the possibility of mass production are guaranteed. In order to make the driving and sensing capacitance of the resonator large enough, the gap between the electrodes and the shell is made of a sacrificial layer, and the capacitance gap is sufficiently uniform and reaches 1.5 μm. The interface control circuit is digitally designed based on FPGA, which gives full play to the advantages of digital system high signal-to-noise ratio and development flexibility. It implements core functions such as open-loop frequency sweeping, phase-locked loop, automatic gain control, and AC quadrature error nulling, and improves the performance indicators of the gyroscope. Experimental results show that the quality factor of the gyro system reaches 42554, the resonance frequencies are 5.130kHz and 5.128kHz, and the bias instability reaches 3.4°/hr.