Phase Correction for Dual Modulation of a Phase Locked Loop Oscillator
Original Publication Date: 1996-Jul-01
Included in the Prior Art Database: 2005-Mar-31
It is a well known problem that any attempt to frequency modulate an oscillator that is embedded in a phase locked loop, will lose the modulation frequency components from the modulated spectrum that are lower in frequency than the cutoff frequency of the loop lowpass filter. It is also a well known solution to this problem to simultaneously modulate the reference oscillator of the phase locked loop system with just those modulation frequency components that would ordinarily be removed by the loop.