A 11.5–22GHz dual-resonance transformer-coupled quadrature VCO

A wide-tuning CMOS quadrature VCO (QVCO) is presented that uses a transformer-coupled resonator that enables quadrature coupling and facilitates alternative tuning methods including mutual inductance switching, magnetic tuning, and dual resonance mode switching besides the conventional capacitor tuning. The QVCO, fabricated in 130nm CMOS, can generate quadrature signals in the frequency range of 11.56–18.1 GHz and 18.9–22 GHz. The phase noise was measured −107dBc/Hz at 1MHz offset from 13.3GHz. The QVCO consumes 20–29mW and the output buffers consume 21mW from a 1.2V supply.