An 18.8-to-40.4 GHz reconfigurable multi-mode VCO with wide-band common-mode resonance

This paper presents an 18.8-40.4 GHz voltage-controlled oscillator (VCO) for 5G FR2 band in 65-nm CMOS. This circuit uses two VCO cores to cover a wide tuning range. Each core is based on Class-B LC-VCO structure and equipped with 5-bit switched capacitors to extend its tuning range. The low Q wide-band common-mode resonance is used to optimize phase noise. The simulation results show that the proposed oscillator exhibits a 72.9% tuning range from 18.8 to 40.4 GHz and the phase noise performance is less than -105 dBc/Hz at 1-MHz offset. The figure of merit (FoM) is better than 186 dBc/Hz at 1-MHz offset in full frequency band. A state-of-the-art FoM
T
of 203.4-207.7 dBc/Hz at 1-MHz offset is achieved with power consumption of 4.63-6.86 mW. The variation range of FoM and FoM
T
is 3.7 dBc/Hz over the full frequency range.