High Resolution Differential Capacitance Detection Scheme for Micro Levitated Rotor Gyroscope

A differential capacitance detection circuit aiming at detection of rotating angle in a novel levitation structure is presented. To ensure the low non-linearity and high resolution, noise analysis and non-linearity simulation are conducted. In the capacitance interface, an integral charge amplifier is adopted as a front end amplifier to reduce the parasitic capacitance caused by connecting wire. For the novel differential capacitance bridge with a coupling capacitor, the noise floor and non-linearity of the detection circuit are analyzed, and the results show that the detecting circuit is capable of realizing angle detection with high angular resolution and relative low non-linearity. With a specially designed printed circuit board, the circuit is simulated by PSpice. The practical experiment shows that the detection board can achieve angular resolution as high as 0.04° with a non-linearity error 2.3%.