A X-Band ${\rm I}/{\rm Q}$ Upconverter in 65 nm CMOS for High Resolution FMCW Radars

Abstract

This work presents a CMOS X-band I Q upconverter for a FMCW radar system. The use of passive current mixers allows to address the main drawbacks of CMOS technology, namely flicker noise and reduced linearity due to low supply voltage, paving the way to monolithic integration with digital intensive baseband circuitry. Prototypes were built in a 65 nm digital technology, showing a peak output power of 3 4 dBm at 10.6 GHz with a corresponding HD 3 lower than 40 dBc and an image rejection greater than 41 dB across the 9.5-12 GHz LO band, while adding negligible phase noise to the output signal. The circuit occupies an area of 0.91 mm 2 and consumes 192 mW. Index Terms-Direct digital synthesis (DDS), frequency-modulated continuous-wave (FMCW), X-band upconverters.