Patent ID: 8378751

Claim:
An apparatus for generating an output signal at an output frequency, the apparatus comprising: a frequency synthesizer including: a fine tuning loop operative to: receive a reference signal at a reference frequency; and generate a fine tuning signal at a first frequency adjustable in fine steps, wherein the first frequency is determined by multiplying the reference frequency by a non-integer ratio; and a coarse tuning loop coupled to the fine tuning loop and operative to: receive the reference signal; and generate the output signal at the output frequency, the output frequency being determined based on the first frequency and a second frequency, the second frequency adjustable in coarse steps, wherein a closed-loop bandwidth of the frequency synthesizer is based on noise shaping, and wherein the noise shaping is based on an oversampling ratio; wherein the coarse tuning loop includes a mixer operative to generate a coarse tuning signal at the second frequency, wherein the coarse tuning signal has a first sideband defined by a difference between the output frequency and the first frequency, and wherein the coarse tuning signal has a second sideband defined by a sum of the output frequency and the first frequency.