一种新型超高精度频标比对系统的设计

Design for novel ultra-high precision frequency standard comparison system

提出了一种基于相检宽带测频技术的新型高精度频标比对设计方案。利用频率信号间相位差变化的规律性,在两相位重合处建立测量闸门,克服了传统频率测量中存在的±1个计数误差的问题。通过附加延时可调电路减少相位重合点的个数并在相位重合控制电路的帮助下有效地捕捉最佳相位重合点,进而降低测量闸门开启和关闭的随机性,大大地提高了系统的测量精度。实验结果和分析表明了该方案设计的合理性和先进性,其实际测量精度可达10-13/s量级,明显优于传统测频方法的测量精度。结合CPLD片上技术,新方案设计的频标比对系统,结构简单,成本低廉,具有广泛的推广和应用价值。

Based on the technique of phase coincidence detection in a wide frequency range, a new design scheme of high precision frequency standard comparison is proposed. Using the regularity of phase difference variation between two frequency signals, a measurement strobe exactly at the phase coincidence is built; in this way ±1 count error that exists in traditional frequency measurement can be eliminated. Phase coincidences can be decreased by adding delay adjustable circuit and the optimal phase coincidences can be seized easily with the help of phase coincidence control circuit, which will reduce the randomicity of the measurement strobe on-off; in this way the system measurement precision is improved greatly. Experiments show that its actual measurement precision can be as high as 10^-13/s, it is visibly better than traditional ones. Combined with CPLD on-chip technique, the new frequency standard comparison system has the advantages of simple structure and low cost, so it is of great value for extension and application.