输入信号的占空比对异或门混频器差频输出的影响

在基于频率输出的传感器测量电路设计中，经常碰到的一个问题是如何高精度测量由测量参数引起的小频率增量。将测量信号和参考信号经过混频器混频，通过低通滤波获得两信号差频输出的方法可解决这个问题。与其他数字混频器相比，异或门混频器在处理两准数字信号差频时有无可比拟的优势。通过理论分析、仿真和实际电路实验，考察了输入信号占空比的变化对异或门混频器差频输出性能的影响。结果表明：两输入信号为占空比50％的方波时，并或门混频器的差频输出性能最佳，滤波电路相对简单；随占空比的变化，异或门混频器的差频输出性能逐渐变差，需要辅以比较复杂的滤波电路。

Influence of input duty cycle on difference frequency performance based on XOR gate mixer

In the design of measuring circuits based on frequency transducers it is frequently necessary to measure small frequency increments,Which was caused by the change of the measured parameter.In general,The mixer receives inputs both from the reference oscillator and the monitor oscillator and a low pass filter produces an output which is the difference of the two input frequencies.An XOR gate mixer has better performance than other digital mixers for two quasi-digital signals frequency difference.The output c...