Oscillator phase noise sets a major limitation to the performance of high-capacity millimeter-wave wireless links. Within the framework of the DRAGON project, a team of researchers in the University of Pavia has developed a novel oscillator circuit topology capable to reach ultra-low phase noise leveraging the series resonance of a tank. Compared to the parallel resonance, the series resonance allows to significantly rise the active power on the tank, thus leading to an ultra-low phase noise with low voltage supply. A VCO test chip in the STMicroelectronics BiCMOS 55nm technology reaches -138dBc/Hz @ 1MHz offset from 10GHz with 1.2V supply and -190dBc/Hz FoM. The phase noise is at least 10dB lower than what achieved by parallel-resonance LC VCOs in silicon at similar frequency so far.
A technical paper has been accepted for presentation at the upcoming International Solid-State Circuits Conference 2022 (ISSCC),
A. Franceschin, D. Riccardi, A. Mazzanti: “Series-Resonance BiCMOS VCO with Phase Noise of -138dBc/Hz at 1MHz offset from 10GHz and -190dBc/Hz FoM”
Conference website: https://www.isscc.org/
Technical program: https://www.isscc.org/program-overview