A 4-port-inductor-based VCO coupling method for phase noise reduction

A 4-port-inductor-based VCO coupling technique is introduced to improve VCO phase noise performance. Complete design steps including resonant network design and circuit topology selection are discussed and prototype designs have been demonstrated to verify the analysis. The proposed 12.8 GHz CCVCO design achieves phase noise of -116 dBc/Hz at 1 MHz offset, a tuning range of 31.4%, FOM and FOM
_T
of 184 and 194 respectively.