锁相环自锁定技术的研究及应用

Design and application of a phase-lock ring circuit(PLL)with self-locking circuit

利用LC电路的振荡频率在回路参数出现变化时会明显变化这一特征,可以根据频率的改变量实现多项测量功能。测量中是依赖LC电路振荡频率的改变量得到测量结果。要想精确测量出瞬时频率差,就要求实现初始频率和当前频率的运算,初始频率的保持是测量过程关键。本文通过对锁相环自锁定技术的研究,从压控振荡器(VCO)的控制电压入手,实现频率的自锁定。实践证明,利用自锁定技术较好地解决了这一问题。

The oscillation frequency of an LC circuit will change as the parameter in the circuit loop changes value. Therefore, the measurement of multi-type functions can be realized by using the changes of oscillation frequency. However,how to obtain the precise frequency difference still remains challenge. The design of a novel phase-lock ring circuit （PLL） with self-locking mechanism is presented in this article. The basic phase-lock ring circuit consisted of phase-comparator,low-pass filter, and voltage controlled oscillator （VCO）. A self-locking circuit including voltage comparator, reverse adder, and frequency-voltage converter has been added to the system to control the input voltage of VCO. The precise frequency difference was realized by the self-locking circuit, which can be used for the parameter measurement of various systems such as non-defect detects and magnetoelectricity measurement.