A Low-Voltage Low-Noise Superharmonic Quadrature Oscillator

A qualitative analysis of the large-signal operation of cross-connected LC oscillators at steady state is presented. It provides a physically understandable picture of the amplitude stabilization in these oscillators. Based on the insights gained from the mechanism of operation, a new low-noise, low-voltage ($V_{dd}$ as low as 0.6 V) quadrature oscillator utilizing the superharmonic coupling is proposed and verified with simulation. The same coupling scheme can be extended to multiphase signal generation.