A Tiny Quadrature Oscillator Using Low-Q Series LC Tanks

A new quadrature oscillator topology is proposed, which arranges four low-Q series LC tanks in a ring structure driven by inverters operating in class-D. With a very small area of 0.007 mm
²
that is comparable to conventional ring oscillators, this oscillator has 7-20 dB better phase noise FoM of 177 dB. It is widely tunable for nearly an octave from 2.66 to 4.97 GHz.