Harmonic-balance analysis of microwave oscillators with automatic suppression of degenerate solution

A systematic approach to the frequency-domain analysis of autonomous microwave circuits for which the fundamental frequency of oscillation is unknown is described. A modified formulation of the harmonic-balance technique is used to suppress the degenerate (DC) solution. A novel procedure is introduced for the generation of a starting point for the state-variable harmonics, from which a mixed-mode Newton iteration can be safely started. The overall method leads to the desired steady-state solution in a direct way without requiring trials.