Patent ID: 6995618

Claim:
A phase-locked loop (PLL) for producing a phase-locked oscillation, the PLL comprising: a phase detection module for producing a current representing a phase difference between a feedback signal and a reference signal; a loop filter operably coupled to receive the current and for converting the current into a control voltage; and a voltage controlled oscillator (VCO) operably coupled to receive the control voltage at a VCO input and to produce an oscillation signal responsive to the control voltage wherein the oscillation signal is provided to the phase detection module in a first feedback loop, wherein: the VCO further comprises a phase adjustment module for reducing phase noise in the oscillation signal, the phase adjustment module operably coupled to receive the oscillation signal and to produce a correction voltage to counteract a phase shift resulting from phase noise in the oscillation signal; and wherein the correction voltage is provided to adjust the oscillation signal frequency in a second feedback loop; and wherein the phase adjustment module further includes a plurality of sampling modules coupled to receive the oscillation signal, wherein each sampling module of the plurality of sampling modules samples the oscillation signal over a different time interval to produce a sampled voltage corresponding to a change in the period of the oscillation signal.