Low phase noise oscillator modeling in a system environment

In this paper the modeling of low phase noise oscillators is addressed from the viewpoints of circuit simulation and system simulation. In a first section, a coherent set of tools allowing an accurate and predictive design of low phase noise oscillators is described. For this purpose, the behavior of L.F. noise current sources in large signal operating conditions is detailed. A special emphasis is put on the phase noise simulation tool. Then the design rules leading to a low phase noise is proposed. In the second section the embedding of oscillator model in a frequency synthesizer is analysed from the viewpoint of system analysis. For that purpose an event driven model is given and tested.