With different modulators of fitted parts with broken ratio.

摘要

A fractional-N type frequency synthesizer includes a frequency divider having a selectable integer divide number which is periodically temporarily altered to provide an average rational divide number for the frequency divider. A number of modulator circuits coupled in cascade fashion provide a zero sum modulation signal which varies the value of the frequency divider divisor value such that the net change in divisor value due to the modulation signal is zero thereby reducing phase noise resulting from the temporary altering of the integer divisor value close to the frequency synthesizer carrier frequency. IMAGE