正交锁相放大器在谐振式光学陀螺中的应用

A lightweight and efficient digital quadrature lock-in amplifier is designed to address the problem of sensitivity degradation due to system delay in resonant optical gyros (ROG), and the sources and effects of delay are analyzed on the basis of sinusoidal modulation. Without involving any optical and circuit hardware changes, the quadrature operation is performed by adding one way of synchronous square wave demodulation with a phase difference of 90°, the system delay is eliminated by the collinearity theorem, and the response speed and compatibility are improved by logic assignment and shift operation. Theoretical analysis and simulation results show that the output of square wave demodulation with same frequency and amplitude is 4/π times that of sinusoidal demodulation output, and the sensitivity of gyro can be increased by 27.3%. The experimental results show that the system delay is reduced by 1.5 μs and the gyro sensitivity is further increased by 11.8% with good robustness.