75–85 GHz flip-chip phased array RFIC with simultaneous 8-transmit and 8-receive paths for automotive radar applications

This paper presents the first simultaneous 8-transmit and 8-receive paths 75–85 GHz phased array RFIC for FMCW automotive radars. The receive path has two separate I/Q mixers each connected to 4-element phased arrays for RF and digital beamforming. The chip also contains a build-in-self-test system (BIST) for the transmit and receive paths. Measurements on a flip-chip prototype show a gain >24 dB at 77 GHz −25 dB coupling between adjacent channels in the transmit and receive paths (<-45 dB between non-adjacent channels) and <-50 dB coupling between the transmit and receive portions of the chip.