Yu Zhu, Architect, SpectreRF, Custom IC, Cadence Design Systems Inc.
Helene Thibieroz, Senior Staff Application Engineer, Cadence Design Systems Inc.
Nand Jha, Senior CAD Engineer, Texas Instrument
Ted Blank, Senior Design Engineer, Texas Instrument
John Skaras, Senior Engineering Manager, Texas Instrument

Noise calculation using conversion matrix equation is not applicable to oscillators, because the matrix becomes ill-conditioned at small offset frequency. In this paper, we present the shooting and harmonic balance based phase-noise simulation methods, which solves the AM and PM components in conversion matrix equation separately. The method is enhanced for VCOs with voltage regulator of large time-constant. Phase-noise curves from different methods. The importance of the oversampling is discussed for VCOs followed by a buffer. VCOÕs injection pulling effect is simulated using two-tone harmonic balance method.