A 76-81 GHz CMOS mmW quadrature down-conversion mixer for automotive radar applications

This paper presents a mmW quadrature down-conversion mixer for 76-81 GHz automotive radar applications. A transformer-based gm-boosting method and a new cascode inter-stage network are proposed to improve the gain of preamplifier. A pair of cross-coupled transistors are exploited to bleed dynamic current into mixer core to reduce noise figure while utilizing its negative resistance to improve conversion gain. The mixer is implemented in a 55-nm CMOS process and the measurement results show that the BW_-3dB is 5.5 GHz, the peak gain is 4.1 dB with <0.16 dB I/Q mismatch, the input P1dB is up to -6 dBm and the minimum noise figure (NF_min) is 19 dB while dissipating 40mWof power. The achieved FOM is up to 0.02.