A CMOS differential DCO with amplitude stabilization for 24GHz automotive radars

Abstract

This paper presents a 24 GHz CMOS Colpitts-Clapp Digitally Controlled Oscillator (CC-DCO) with an automatic amplitude stabilization to improves the Phase Noise (PN) performance. Amplitude stability is favorable to suppress the amplitude-to-phase conversion. The DCO is implemented in 65 nm TSMC CMOS process. The Tuning Rang (TR) is from 22 GHz to 29 GHz that is required for a 24 GHz Short Range Radar (SRR). The CC-DCO consumes a maximum of 19 mW. Oscillating at 24 GHz, the PN of −104 dBc=Hz at 1MHz offset frequency is achieved. The amplitude of oscillation varies by 4.56% across 29% TR.