A 77 GHz automotive radar transmitter in 65-nm CMOS

A single side band(SSB) 77 GHz transmitter for radar automotive applications is presented in this paper. The direct conversion transmitter consists of a SSB sub-harmonic up-convertion mixer and a 4-stage power amplifier(PA). The 38 GHz passive coupler and balun are designed to provide IQ differential LO from external input to drive the mixer. The proposed transmitter is fabricated in 65-nm CMOS. The measured transmitter has 1-dB output compression point of -2 dBm and a saturation output power of 0 dBm at 77 GHz. The leakage from LO to RF output is less than -33 dBm and the output matching is better than -18 dB from 65 to 80 GHz. The proposed transmitter power consumption is 130 mW and the silicon die-size is 1.0 × 2.7 mm².