Differential Cross-Coupled CMOS VCOs with Resistive and Inductive Tail Biasing

Todays Wireless Communication Systems need very high performance VCOs. In many cases, phase noise levels better than -100 dBc/Hz@100 kHz have to be reached with a power consumption lower than 10 mW. This work presents a 1.8 GHz CMOS VCO with a phase noise of -113 dBc/Hz@100 kHz, where a bias resistor avoids the MOS active current source and its related noise, while a tail inductor allows truly differential operation.