Patent ID: 6636086
Filing Date: 2003-10-21
Classification: H03B,H03L

Abstract:
A frequency synthesizer comprising:an output oscillator for generating an output signal whose frequency, FOUT, is determined by an oscillator input signal; a difference circuit for generating a sampled signal having a frequency, Fsif=FOUTâˆ’FOFFSET; a reference circuit for generating a reference signal having a frequency Fref, said reference circuit comprising a reference oscillator for generating a reference oscillator output signal having a frequency F1 and a first division circuit for generating a signal having a frequency equal to F1 divided by R; a feedback signal generating circuit for generating a feedback signal having a frequency, Ffb, said feedback signal generating circuit comprising a second division circuit and wherein Fsif/Ffb<10; and a comparator for comparing said reference signal and said feedback signal and generating said oscillator input signal, wherein one of said first and second division circuits is a Fractional-N Divider having a division factor, N.F, greater than 10.