4. Antennas for 24 and 79GHz automotive radar applications

4.1 Introduction and specifications

Vehicle-mounted radars are designed to prevent or anticipate road accidents, which were responsible for over 40,000 deaths in Europe in 2010. To date, these systems operate in the 24GHz band (200MHz narrowband or 5GHz wideband) and 77GHz for ACC (Auto-Cruise-Control) long-range radars. Long-range radars (LRR: Long Range Radar) must be able to detect other vehicles up to 200m away, with antennas having a narrow beam (3-4°) and an angular sector of view of around ±10°. Short-range radars (SRR: Short Range Radar) are designed to detect obstacles up to 30m away, with antennas featuring a wider beam (28° in azimuth and 4° in elevation) and an angular sector of view of around ±70°, to provide information on the vehicle's environment (presence of pedestrians,...