有些锁相环路的被锁信号时常出现中断,例如由电机拖动的迈克尔逊干涉仪的输出信号,当电机换向时,干涉信号的频率由某个定值突然减至零,再回升至原频率,这就必然引起锁相环路失锁。如果干涉仪动镜可移动的距离较短,即信号中断现象很频繁,那么自动快捕就成为测量中的一个十分重要的问题了。一般说来,输入脉冲信号的锁相环路,几乎都采用锯齿形鉴相器,记忆锯齿顶点的电压,做为鉴相器的输出。图1为鉴相器的典型电路,用电容与结型场 Some PLL lock signal often appear interrupted, for example, by the motor drag Michelson interferometer output signal, when the motor commutation, the interference signal frequency suddenly dropped from a fixed value to zero, and then rose to The original frequency, which will inevitably lead to phase-locked loop loss of lock. If the interferometer movement mirror can move a short distance, that is, the phenomenon of frequent signal interruption, then automatic fast capture has become a measurement of a very important issue. In general, the phase-locked loop input pulse signal, almost all the use of jagged phase detector, jitter vertex voltage memory, as the phase detector output. Figure 1 shows the typical circuit of the phase detector, using capacitors and junction field