13.6 mW 79 GHz CMOS Up-Conversion Mixer With 2.1 dB Gain and 35.9 dB LO-RF Isolation

We report a 79 GHz mixer for direct up-conversion using 90 nm CMOS technology. In the mixer, an enhanced double-balanced Gilbert cell with current injection is used to reduce power consumption, and dual negative resistance compensation (NRC) is used to improve conversion gain (CG). In addition, it also includes two Marchand baluns: the single LO input signal to differential signal is converted by one of the baluns, and the differential RF output signal to single signal is converted by the other. The mixer consumes 13.6 mW, achieving IF-port input reflection coefficient (S₁₁) of - 11.4 dB at 0.1 GHz, LO-port input reflection coefficient (S₂₂) of - 12.2 ~ - 28.7 dB for frequencies 75-90 GHz. At IF of 0.1 GHz and RF of 78.1 GHz, the mixer achieves CG of 2.1 dB and LO-RF isolation of 35.9 dB, the best CG and isolation results ever reported for a W-band silicon-based mixer with power consumption lower than 15 mW.