窄脉冲相干激光雷达偏频锁定系统仿真研究

鉴于偏频锁定技术在激光外差探测和激光雷达等方面的广泛作用，基于可编程逻辑器件，设计了适用于窄脉冲激光外差信号的偏频锁定控制系统。在设计中，使用超高速电压比较器进行波形变换、多脉冲鉴频和大概率均值滤波进行数字鉴频，采用小步长快速控制方法进行调频，利用数模转换器和线性放大电路输出调频信号。借助信号发生器产生40ns脉宽的模拟外差信号对系统进行了仿真，实现了设计功能。对系统进行鉴频和调频测试，在40ns脉宽时鉴频误差范围为-7.5MHz～+7.7MHz。

Simulation of frequency-offset-lock system for narrow pulse coherent laser radar

The frequency-offset-lock control system which is applied to the heterodyne signal of narrow pulse laser is designed based on the programmable logic device since the frequency-offset-lock technology is widely used in laser heterodyne detection and laser radar. In the design, ultrahigh-speed comparator was applied for the waveform conversion, the multi-pulse frequency discrimination and maximum probability median filtering were adopted for the digital frequency discrimination, the fast control by small step was used for the frequency modulation, and the D/A convertor and linear magnification circuit were used to output the frequency modulated signal. The simulated heterodyne signals with the 40ns pulse width generated by the signal generator were employed to simulate the whole system, and the design function was realized. The simulation experiments show that the error range of the frequency discrimination gained by the designed frequency discriminator and modulator is -7.5MHz～+7.7MHz when the pulse width is 40ns.