A 20 GHz sub-1 V low noise amplifier and a resistive mixer are designed and fabricated in 90 nm CMOS technology. The LNA achieves a good linearity along with a moderate gain and noise figure. For instance, at 0.9 V supply voltage, 8.8 dB of gain and 5.2 dB of noise figure, as well as 7.0 dBm of IIP3 are obtained. This LNA can work properly even at a supply voltage as low as 0.66 V. It achieves 8.0 dB of gain, 5.3 dB of noise figure, and 3.8 dBm of III3. The DC consumption is 16.8 mW and 11 mW for a supply voltage of 0.9 V and 0.66 V, respectively. This is the first report of a high frequency CMOS LNA operating at such low supply voltage and low DC power dissipation. Moreover, a 20 GHz resistive passive mixer is presented, exhibiting a high IIP3 of 19 dBm, a moderate conversion loss of 7.6 dB, and a low noise figure of 4.35 dB. It consumes no DC power. Thus, these two circuits are suitable to be applied in a high frequency CMOS front-end operating with sub-1V supply. 0-7803-9433-X/05/$20.00 ©2005 IEEE. APMC2005 Proceedings