Patent ID: 8258877

Claim:
A feed-forward phase-noise-cancellation circuit comprising: a phase-noise measurement block adapted to measure a phase noise of an oscillator; and a variable phase-shifter configured to modulate the phase of the oscillator with the measured phase-noise, and subtract the phase noise from the oscillator; or a mixer or frequency multiplier to subtract the measured phase noise from the oscillator output phase, wherein the phase-noise measurement block is configured as a delay line frequency discriminator followed by an integrator; and the integrator following the delay line frequency discriminator comprises a voltage-Controlled oscillator; or the delay line frequency discriminator comprises a quadrature frequency discriminator that has a configuration that receives two inputs 90 degrees out of phase; or the feed-forward scheme has a main, non-frequency discriminated path and a delay compensation line is used in the main, non-frequency discriminated path of the feed-forward scheme; or the circuit further comprises a cascaded multi-stage of two or more feed-forward phase-noise cancellation circuits.