A Compact CMOS 76–82 GHz Super-Harmonic VCO with 189 dBc/Hz FoM Operating based on Harmonic-Assisted ISF Manipulation

Abstract

A compact super- harmonic voltage-controlled oscillator (VCO) for mm-wave radar applications employing a novel distributed structure operating at a center frequency of 78.9 GHz is presented. An state-of-the-art phase-noise performance is achieved by leveraging the strong presence of second harmonic at the output. This new VCO structure operates based on the minimization of the thermal noise contribution for fundamental signal and thus, improves the phase noise. The V CO is fabricated in 65nm Bulk CMOS technology and attains a measured phase-noise of −109.82 dBc/Hz at 1 MHz offset frequency, corresponding to a figure-of-merit of 189dBc/Hz. The VCO also demonstrates 7 % of frequency tuning, 4.6 % efficiency, and −0.6 dBm peak output power. To the best of our knowledge, this is the highest reported FOM for a super-harmonic CMOS oscillator operating at this frequency band.