A noise circulating VCO with an intrinsic injection locking tripler

Abstract A noise circulating voltage‐controlled oscillator (VCO) with an intrinsic injection locking tripler is introduced. Based on the conventional frequency tripling scheme, by integrating the injection transistor pair into the fundamental VCO core, the current of the fundamental VCO core is reused by the injection transistor pair, and the phase noise is reduced due to the noise circulating behavior. The proposed VCO may achieve the fundamental and 3rd harmonic outputs, simultaneously. A protype design is implemented in a standard 65 nm CMOS process, with a tuning range of 33.68–40.11 GHz (17.4%). The phase noise at 1‐MHz offset varies between −101.2 and −97.9 dBc/Hz among the tuning range. The FoM T is in the range of 190.4 and 187.9 dBc/Hz, at 1‐MHz offset.