A Wide-Tuning Dual-Band Transformer-Based Complementary VCO

A dual-band wide-tuning range complementary LC-VCO is reported that utilizes additive and subtractive coupling of transformer inductances. Complementary circuitry in the VCO enables the frequency tuning range to be extended with boosted positive loop gains. Implemented in 65 nm CMOS, the measured results show frequency tuning range of 56% and 33% at 7.5 and 18.25 GHz center frequency, respectively, and phase noise of -98 ~ -112 dBc/Hz (FoM
_T
of 187 ~ 202) at 1 MHz offset while dissipating 1.7 ~ 9.9 mW.