Low and Stable Phase Noise W-Band Capacitive Cross Coupled VCO across tuning range in 90 nm SiGe BiCMOS Technology

A single-core capacitive cross-coupled VCO with a push-push architecture is implemented in 90 nm SiGe BiCMOS technology for high-performance automotive radar applications. The implemented VCO achieved a measured tuning range from 89.9 GHz to 95.4 GHz with a best phase noise of -104.8 dBc/Hz at 1MHz offset frequency at 25 °C. This is the record value of phase noise achieved for a single core VCO at the mentioned operating frequency range according to the best knowledge of the authors. The VCO has a stable phase noise with a variation of approximately 1dBc/Hz across the complete tuning range. Optimizing the VCO current setting also reduces the phase noise variation across temperatures. Additionally, the VCO has achieved excellent supply-pushing performance with 30 MHz/V. The VCO test chip consumes a current of 85 mA, whereas the VCO core needs a current of 23 mA with a single supply of 3.3 V.