与激励信号相位相关干扰背景下信号的测量

Signal measurement in presence of interference's phase correlating with excitation

针对与激励信号相位相关干扰背景下的信号测量,提出了一种新的方法。在深入分析VFC型模数转换器低通特性的基础上,得出合理选择VFC输出脉冲测频的计数周期能完全消除正弦或非正弦周期的干扰,再利用干扰和激励相位相关这一条件,设计了能自动跟踪激励频率去消除相关干扰对测量结果影响的电路,经测试,该方法能很好地满足设计要求。和其他方法相比,它具有电路简单、成本低、可灵活调整测量时间和分辨力的优势。

A novel method on signal measurement in the presence of interference＇s phase correlating with excitation is proposed. Based upon the analysis of voltage-to-frequency convertor＇s （ VFC ） low-pass property, conclusion that correct set of the count-time of the VFC＇s output pulse can completely reject sinusoid or nonsinusoid interference is achieved, furthermore, makeing use of interference＇ s phase correlating with excitation, a circuit capable of effectively removing the phase correlated interference according to the excitation＇s frequency is designed. Tests indicate that this method can satisfy with the requirement, compared with other methods, the method is simple circuit, low-cost and flexible adjustment of resolution and measuring time.