Local oscillator (LO) generator with multi-phase divider and phase locked loop

摘要

Techniques for generating a local oscillator (LO) signal are disclosed. In one design, an apparatus includes an oscillator, a divider, and a phase locked loop (PLL). The oscillator receives a control signal and provides an oscillator signal having a frequency determined by the control signal. The divider receives the oscillator signal and generates multiple divided signals of different phases. The PLL receives a reference signal and a selected divided signal and generates the control signal for the oscillator. The divider is powered on and off periodically and wakes up in one of multiple possible states, with each state being associated with a different phase of the selected divided signal. Phase continuity of the selected divided signal is ensured by using the divider in a feedback loop with the PLL. The PLL locks the selected divided signal to the reference signal, and the selected divided signal has continuous phase due to the reference signal having continuous phase.

主权项

1. An apparatus comprising:
an oscillator configured to receive a control signal and provide an oscillator signal having a frequency determined by the control signal; a divider configured to receive the oscillator signal and generate a plurality of divided signals of different phases; and a phase-locked loop (PLL) configured to receive a reference signal and a selected divided signal among the plurality of divided signals and to generate the control signal for the oscillator, wherein the divider is periodically powered on and off and wherein the selected divided signal has continuous phase.