Patent ID: 6822519
Filing Date: 2004-11-23
Classification: H03D,H03J,H03L

Abstract:
A method of locking a voltage-controlled oscillator (VCO) to a reference signal from a reference frequency divider to thereby provide an output signal with a selected output frequency wherein said VCO and a loop frequency divider are coupled in a phase-locked loop that receives said reference signal, the method comprising the steps of:positioning a half-rate frequency divider with a divisor X between said VCO and said loop frequency divider to provide said output signal; setting the divisor R of said reference frequency divider to obtain a selected reference frequency of said reference signal; setting the divisor M of said loop frequency divider to the ratio between said selected output frequency and said selected reference frequency; fixing the control voltage of said VCO at a predetermined point in the range of said control voltage; coupling a predetermined number of band capacitors to said VCO; successively incrementing said divisor X; subsequent to said incrementing step, successively altering said number; halting said incrementing and altering steps in response to counter outputs of said reference frequency divider and said loop frequency divider which indicate relationships between a current output frequency and said selected output frequency that facilitate phase lock; and releasing said VCO control voltage to phase lock said VCO to said reference signal.