This paper presents a 79GHz variable gain low-noise amplifier (LNA) and power amplifier (PA), both implemented in 28nm CMOS, and measured at temperatures from 27℃ to 125℃. The 4-gain steps LNA and the 17dB gain PA are based on a multistage common source neutralized push-pull topology. The LNA achieves a gain of 23.8dB and a noise figure (NF) of 4.9dB, and the PA achieves a maximum power added efficiency (PAE) of 13.8% and a saturated output power (Psat) of 12.3dBm. At 125℃ both the LNA and the PA are functional with NF < 7dB and Psat >11dBm. This paper demonstrates the feasibility of using scaled CMOS technology (28nm) for automotive radars.Index Terms -Automotive Radar, Spillover, 79GHz CMOS LNA , 79GHz CMOS PA, Variable gain.