A 79 GHz Phase-Modulated 4 GHz-BW CW Radar Transmitter in 28 nm CMOS

Millimeter-wave sensors perform robust and accurate remote motion sensing. We propose a 28 nm CMOS Radar TX that modulates a 79 GHz carrier with a 2 Gsps Pseudo-Noise sequence. The measured modulated output power at 79 GHz in 4 GHz BW is higher than +11 dBm (27°C), while the spurious emissions are below -20 dBc, fully satisfying the spectral mask regulations. The output RF BW where we can lock the injection-locked LO is 13 GHz. Overall, the TX draws 121 mW from a 0.9 V supply resulting in a record efficiency above 10%. More importantly, the TX is functional up to 125°C still providing more than +7 dBm output power over the same RF BW.