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 similar to -112 dBc/Hz (FoM(T) of 187 similar to 202) at 1 MHz offset while dissipating 1.7 similar to 9.9 mW.