Fast simulation techniques for phase noise analysis of oscillators

This work proposes two novel simulation techniques that allow for fast and accurate predictions of phase noise in oscillators even adopting inexpensive software, such as PSpice. The traditional harmonic tone insertion is initially discussed, by applying it to a LC-tuned oscillator taken as benchmark. Then a first, much faster technique based on sensitivity analysis is proposed, which is suitable for the estimation of phase noise due to low-frequency sources e.g. l/f noise. Finally, the high-frequency noise sources contributions to SSCR are analyzed through another alternative method based on the frequency demodulation of the carrier. Both of these methods allow the designer to promptly identify the noise sources mainly responsible for the carrier instability and to accomplish the optimization for low phase noise of the synthesizer.