A fractional-N frequency synthesizer is disclosed wherein the multi-modulus frequency divider in the feedback path of the phase locked loop is controlled by a delta-sigma modulator to achieve the desired division ratio. The fractional input control signal to the delta sigma modulator is dithered to break...http://www.google.co.uk/patents/US20030137359?utm_source=gb-gplus-sharePatent US20030137359 - FRACTIONAL-N FREQUENCY SYNTHESIZER WITH SINE WAVE GENERATOR
