Electronically scanned millimeter-wave radar for pre-crash safety and adaptive cruise control system

An objective of developing intelligent transport systems (ITS) is to enhance driving convenience. As an ITS technology that meets this objective, an adaptive cruise control (ACC) system has already been commercialized. Another objective is to enhance the vehicle safety performance. With the aim of attaining this objective, we have developed a Pre-crash Safety system by evolving the ITS technology used in ACC. The Pre-crash Safety system is designed to predict an unavoidable collision and activate Pre-crash Seatbelt and Pre-crash Brake Assist well in advance of the collision to mitigate occupant injury caused by the collision. A millimeter-wave radar sensor is indispensable to the Pre-crash Safety system. This present paper describes the electronically scanned millimeter-wave radar sensor developed for use in the system. This radar is physically compact while providing high object recognition performance. This is due to the phased array technology employed for the first time in the world for automotive radar. Other features of the radar include a "high-efficiency planar antenna, "high-power and low-loss monolithic microwave ICs (MMICs) and millimeter-wave circuit" and a "high-speed digital-beam-forming (DBF) algorithm".