Common-mode stability in low-power LO drivers

A resonator loaded LO buffer is shown to be potentially common mode unstable, when it is connected to drive a double balanced current steering mixer. The stability margin is found to be inversely proportional to the quality factor of the resonator load and, therefore, to the power consumed by the LO buffer. A known solution to the problem is compared with two proposed ones. The approaches differ in terms of current consumption, occupied voltage headroom and area.