A 65 nm CMOS varactorless mm-wave VCO

We present a cross-coupled 60 GHz differential LC voltage controlled oscillator (VCO) implemented in 65 nm CMOS technology. To eliminate the need for varactors, the frequency tuning is implemented using transformers in the resonator, where the effective inductance can be controlled by injecting current into the secondary windings. Measurements show an average current consumption of 15 mA from a 1.2 V supply, resulting in a minimum FOM of -182.4 dBc/Hz, and the frequency versus tuning current in the secondary is close to linear. The die area of the oscillator core, including the transformers, is 70 um × 85 um.