本文证明在注入锁定情况下,压控注锁振荡器实质上是压控可变相移振荡器(VCPSO)。分析了由鉴频器(FD)、鉴相器(PD),以及FD加PD同VCPSO构成的三种环路,并分别给出了等效框图,及相应的闭环相位传递函数。为了与一般锁相环路相区别,分别称之为Ⅰ、Ⅱ、Ⅲ类零阶最小剩余相位误差环。 This paper demonstrates that a voltage-controlled lock-up oscillator is essentially a voltage-controlled variable phase-shift oscillator (VCPSO) in the case of an injection lock. The three kinds of loops composed of FD, PD, FD plus PD and VCPSO are analyzed. The equivalent block diagram and the corresponding closed-loop phase transfer function are given respectively. In order to distinguish with the general phase-locked loop, they are respectively referred to as the zero-order minimum residual phase error loop of Ⅰ, Ⅱ, Ⅲ.