Computation of period sensitivity functions for the simulation of phase noise in oscillators

Accurate phase noise simulation of circuits for radio frequency applications is of great importance during the design and development of wireless communication systems. In this paper, we present an approach based on the Floquet theory for the analysis and numerical computation of phase noise that solves some drawbacks implicitly present in previously proposed algorithms. In particular, we present an approach that computes the perturbation projection vector directly from the Jacobian matrix of the shooting method adopted to compute the steady-state solution. Further, we address some problems that arise when dealing with circuits whose modeling equations do not satisfy the Lipschitz condition at least from the numerical point of view. Frequency-domain aspects of phase noise analysis are also considered and, finally, simulation results for some benchmark circuits are presented.