A Transformer Based Low Phase Noise Ultra-Low Power VCO for Vehicular Communication System

This paper presents a low voltage ultra-low power VCO for IEEE 802.11p vehicular communications application based on a 0.13-$\mu$m CMOS technology. Compact and multiple strongly-coupled LC tanks are adopted for the frequency selection with improved quality factor and low phase noise. The cross-coupled transistors of VCO core work in the sub-threshold region rather than saturation to further reduce the current dissipation. The proposed VCO achieves −113.9 dBc/Hz phase noise at 1 MHz offset at center frequency 5.9 GHz and 11.1% tuning range with only 334 $\mu$W power consumption and 0.13 mm$^{2}$ compact chip area.