Modeling of Oscillator’s Phase Noise: A Comparison between the Leeson’s Model and the Power-law Model

In order to analyze and estimate the phase noise impact on the performance parameters, such as the short-term frequency stability/the Allan deviation, the timing jitter, the phase and frequency jitter etc. of a frequency source and also to estimate the effect of carrier phase noise on the BER performance of a data communication link, we need to represent the measured phase noise spectrum plot of a frequency carrier by the appropriate mathematical models. The paper describes two such models namely, the Leeson’s model and the Power-law model to represent analytically the measured phase noise spectrum plot of a frequency carrier. Using these models described here, the measured phase noise spectrum plot of a 10 MHz Rubidium Atomic Frequency Source (RAFS) of IRNSS (Indian Regional Navigation Satellite System) system and also that of a 10 MHz Rubidium standard OCXO (Oven Controlled Crystal Oscillator) have been represented analytically. The estimated SSB (Single Sideband) phase noise density values thus obtained from these fitted models are then compared with the actual measured values of SSB phase noise density.