An 18.3~42.1GHz Octave Frequency Tuning Class-C Quadcore VCO Achieving 204.5 dBc/Hz FOMT

This article reports an octave millimeter-wave (mmwave) oscillator in a 28nm CMOS process. Combining class-C operation and mode-switching technology, the proposed VCO achieves an ultra-wide tuning range with low power consumption. Four reconfigurable modes are generated by magnetic and electric coupling. A dynamic bias circuit is utilized to ensure a robust start-up of all four oscillation cores. Based on the post-layout simulations, the VCO exhibits a wide turning range from 18.3 to 42.1GHz and low phase noise from -102.7 to -108.6dBc/Hz at 1MHz frequency offset over the whole operating frequency. The class-C quadcore VCO only consumes 6.3~13.2mW from 0.9V supply achieving 204.5 FOM <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T.</inf> The reported FOM and FOM <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> are competitive among VCOs operating in a nearby frequency range.