Computing phase noise eigenfunctions directly from steady-state Jacobian matrices

The main effort in oscillator phase noise calculation lies in computing a vector function called the Perturbation Projection Vector (PPV). Current techniques for PAVE calculation use time domain numerics to generate the system´s monodromy matrix, followed by full or partial eigenanalysis. We present a superior method that finds the PPV using only a single linear solution of the oscillator´s time- or frequency-domain steady-state Jacobian matrix. The new method is better suited for existing tools with fast harmonic balance or shooting capabilities, and also more accurate than explicit eigenanalysis. A key advantage is that it dispenses with the need to select the correct one-eigenfunction from amongst a potentially large set of choices, an issue that explicit eigencalculation based methods have to face.