A 10 GHz low phase noise VCO employing current reuse and capacitive power combining

A VCO employing capacitive power combining to reduce phase noise is presented. A current reuse technique is utilized to improve the phase noise per unit power metric over conventional LC oscillators. The VCO achieves a phase noise of -148.7 dBc/Hz at 20 MHz offset and a tuning range of 9.15-10.6 GHz while dissipating 30 mW from a 1.3 V supply. Implemented in a 45 nm CMOS technology, it achieves an FOM of 188 dBc/Hz while occupying an area of 0.67 mm².