Patent ID: 7157979
Filing Date: 2007-01-02
Classification: H03C,H03L

Abstract:
1. Apparatus including a phase-lock loop, the phase-lock loop comprising an oscillator ( 20 ) for generating a variable frequency signal and having a control input ( 22 ) for controlling the frequency of the variable frequency signal, dividing means ( 30 ) coupled to an output of the oscillator ( 20 ) for dividing the variable frequency signal, phase comparator means ( 40 ) coupled to an output of the dividing means ( 30 ) for generating a comparison signal indicative of a phase difference between the divided variable frequency signal and a reference signal, filtering means ( 50 ) coupled to an output of the phase comparator ( 40 ) means for filtering the comparison signal, coupling means ( 25 ) for coupling an output of the filtering means ( 50 ) to the control input ( 22 ) of the oscillator ( 20 ), further comprising modulation means ( 210 or 400 , 410 ) for causing the comparison signal to be modulated at a plurality of rates, measurement means ( 220 ) for measuring for each of the plurality of rates an indication of the peak-to-peak variation of a control signal applied to the control input ( 22 ) of the oscillator ( 20 ), and adjustment means ( 230 ) operable to adjust a loop gain between the comparator means and the filter means in response to the measurements to obtain a predetermined loop frequency response.