Υ. A. Phillis, "On the rigorous treatment of stability of microwave oscillators," Intern. J. of Electronics, vol. 52, no. 3,pp. 275-282, 1982.doi:10.1080/00207218208901423
https://doi.org/10.1080/00207218208901423
In this paper, the theoretical tools are provided for the solution of the problem of stochastic stability of a class of non-linear systems. The criterion considered is the minimization of entropy which is a measure of uncertainty. Then the problem of stability of microwave oscillators is solved rigorously. The results explain two features of microwave oscillators : phase drift and change of the operating point due to noise.