A 24GHz Digitally Controlled Oscillator for automotive radar in 65nm CMOS

This paper presents a CMOS 24GHz Clapp-Colpitts Digitally Controlled Oscillator (CC-DCO) with 22GHz-29GHz tuning range that is able to address Short Range Radar (SRR) requirements. In order to overcome the major challenge to design a wide tuning range DCO, proper oscillator topology is chosen, specific tuning mechanism is implemented, and design optimization strategies are employed without degrading the Phase Noise (PN) performance. The CC-DCO is implemented with 65nm CMOS process. A wide tuning range of 29% and a fine tuning step of 1.6 MHz are achieved simultaneously. The CC-DCO consumes 10mA from a 1V supply. It shows a PN of -187dBc/Hz at 1 MHz offset frequency, and achieves -268dBc/Hz figure of merit considering the tuning range.