A low-noise transformer-based 1.7 GHz CMOS VCO

A low-noise transformer-based 0.35 /spl mu/m CMOS VCO operates at 1.7 GHz. The VCO core consumes 4.5 mA from 2.5 V, and results in phase noise of -116, -137 and -142 dBc/Hz at 100 k, 600 k and 1 MHz from the carrier, respectively. The tuning range is 107 MHz for 0-2.5 V tuning voltage. The oscillator is based on a transformer-type resonator.