基于异频相位处理的高精度频率测量系统

High Precision Frequency Measurement System Based on Different Frequency Phase Processing

提出了一种基于异频相位处理的高精度频率测量系统的设计方案.在异频鉴相技术的基础上,通过脉宽调整电路减少相位重合点簇中的脉冲个数和附加相位控制电路有效捕捉最佳相位重合点,降低了计数闸门动作的随机性,极大地提高了系统的测量精度.新方案结合现场可编程门阵列片上技术,既保留了相位重合检测技术克服±1个计数误差的优越性,同时也提高了测量速度,简化了测量设备,降低了成本和功耗.实验结果和分析表明了新方案设计的科学性和先进性,其实际测量精度可达10-13s-1量级,明显优于传统测频方法的测量精度,具有广泛的应用和推广价值.

A new design scheme of high precision frequency measurement system is proposed based on different frequency phase processing. Adopting different frequency phase comparison technique, pulse number of phase coincidence clusters can be decreased by pulse width adjustable circuits, and the optimal phase coincidence can be obtained effectively by phase coincidence control circuits, reducing the randomieity of the count strobe action greatly. In this way, the system measurement precision is improved significantly. Combined with FPGA on-chip technique, the new scheme not only retains the superiority that it eliminates ±1 count error based on the technique of phase coincidence detection, but also improves the measuring speed. As a result, the system structure is simplified, and cost and power consumption reduced too. Experiments and analysis indicate that its actual measurement precision can be as high as 10-13 s-1, obviously better than that of traditional methods. Thus, it is of great value in extension and application.