An 8th sub-harmonic injection locked V-band VCO for low power LO routing in mm-wave beamformers

This paper presents an 8^th sub-harmonic injection locked V-band oscillator for low power LO routing in mm-wave beamformers. The VCO uses an inductively cross-coupled transformer for transconductance boosting. Injection is carried out through a customized three inductor transformer connected to achieve twice the coupling strength between any two inductors. The V-band sub-harmonic injection-locked oscillator (SILO) is implemented in a standard 0.13 μm BiCMOS process and occupies an active area of 200 μm × 100 μm. The proposed SILO operates at 0.5 V supply and consumes a total power of 3.72 to 6.57 mW, including the injection source. The SILO shows a free-running tuning range of 17.9% centered at 53.5 GHz. In the injection locking mode, it achieves a minimum locking range of 450 MHz at high band and 1.4 GHz at low band with just -10 dBm input power. The proposed LO routing scheme shows minimum power consumption among state-of-the-art beamformers and thus is the most suitable candidate for LO routing in mm-wave beamformers.