我们介绍二阶锁相环的一种新型电路结构。该结构对于大的初始频率偏移所提供的捕获时间比采用常规锁相环所获得的捕获时间要短几个数量级。当绕过环的时间延迟很短时,这种新型电路也能几乎瞬时地提供频率锁定。而且,当没有失锁时,它能保持频率变化比用常规电路所能保持的频率变化所需时间短数百倍。 We introduce a new circuit structure of second-order phase-locked loop. The structure provides a capture time that is a few orders of magnitude shorter than that obtained with conventional phase-locked loops for large initial frequency offsets. The new circuit also provides frequency lock almost instantaneously when the time around the ring is short. Furthermore, it maintains a frequency change hundreds of times shorter than the time it takes for a conventional circuit to sustain changes in frequency without losing lock.