14.6 A 76-to-81GHz 2×8 FMCW MIMO Radar Transceiver with Fast Chirp Generation and Multi-Feed Antenna-in-Package Array

Millimeter-wave (mm-wave) radar is an essential sensor of advanced driver assistance systems and autonomous driving. Its detection requirement extends from traditional long-to-medium range to emerging short and ultra-short range for surround sensing, which is from sub-1 meter to 40 meters and requires a compact and low-cost solution with fast chirp generation to improve the range resolution [1] -[5]. In [2], 3 transmitters (TX) and 4 receivers (RX) are utilized to create a multi-mode radar transceiver, however its on-board antenna integration solution limits its size and cost for short-distance applications. In [3], 12TX and 16RX phase-domain multiple-input multiple-output (MIMO) radar is presented. However an external PLL is required, and the digitalprocessing power consumption is high. Furthermore its size and cost are not suitable for short and ultra-short applications. In [4], a compact 1TX and 1RX frequency-modulated continuous-wave (FMCW) radar is applied with an antenna-in-package (AiP) for short-distance applications, however its detection range is limited to only 20meters. This work presents a compact 76-to-81GHz FMCW MIMO radar with fast chirp generation and integrated with an AiP array in embedded glass fan-out (eGFO) technology for short and ultra-short range application. A fast-modulated chirp signal is especially crucial in MIMO radar for improving range resolution with update rate, and it also moves IF frequency away from the 1/f noise corner. Thanks to the dynamic bias technique, the chirp rate is improved to 312.5MHz/μs and the maximum modulation bandwidth is 7.2GHz. In addition, the 2TX and 6RX array antennas are integrated in package, and effective isotropic radiated power (EIRP) of the TX antenna is improved by 7.5dB by a coaxial feeding structure in eGFO technology with multi-feed antenna technique.