Effective behavioral models for ΣΔ Fractional-N Frequency Synthesize phase noise prediction

A methodology is presented for predicting the phase noise of the ΣΔ Fractional-N Frequency Synthesize that is both accurate and efficient based on sampling the noise voltage in the time domain. An accurate Voltage Control Oscillator (VCO) noise model is presented, including both thermal noise and 1/f noise. The behavioral model provides a great speed-up over the transistor level simulation and an accurate phase noise prediction.