A Low Profile Microstrip Array Antenna for Automotive Radar

In this paper, a 79 GHz low-profile microstrip array antenna for automotive radar is designed and fabricated. The automotive radar has the characteristics of collision avoidance. This radar within the architecture can limit the unique frequency of accidents, which has the prospect of extended application. A millimeter wave radar of a certain specification was adopted as the detection accessory of this anti-collision architecture, which cooperated with the driver to adjust the vehicle speed and effectively control the distance between vehicles. The unique device of millimeter-wave automotive radar can distinguish the front object within the range of 500 meters. This identification function is not affected by various times and adverse weather conditions, and can issue a variety of prepared alarms according to the unique distance between obstacles. In the automobile radar system, the transceiver antenna is one of its important components. In order to satisfy the different detection distances and reduce the actual size and weight of the antenna, microstrip array with low profile is a good choice. To design the antenna, an array of 15 elements in a row is first designed to form a one-dimensional radiating comb feed microstrip element array. Finally, a 10-row two-dimensional array is fabricated and a power divider is used to complete the antenna design. The goal of designing this antenna is to obtain an appropriate radiation pattern with high gain and low sidelobe. The measured side lobe level of the antenna in E and H plane is better than -23 dB and -18 dB. The beam width is about 9°and 11° in the both planes. The measured peak gain reaches 22.5 dB.