Using Floquet eigenvectors in the design of electronic oscillators

Wide attention has been paid in the recent literature to reliable and efficient modeling of phase noise in oscillators with particular regard to limitations related to the passive element quality factors and higher noise in short channel CMOS transistors. A model based on linearization along the orbit and Floquet eigenvector decomposition seems to properly describe the phase noise, and is now implemented in widely used simulation tools. The major drawback of this approach is the lack of circuit insights that could guide designers in their work. We present an application of Floquet eigenvectors information as a tool of analysis and comparison between different topologies in particular the well known differential oscillator and the Abidi "tail filter" CMOS architectures.