Design of 77 GHz Narrow Beamwidth Antenna for UAVs Obstacle Avoidance Radar

Obstacle avoidance technology is critical for Unmanned Aerial Vehicles (UAVs) in kinds of applications. Among several feasible obstacle avoidance technologies, millimeter-wave radar is promising with advantages of high precision, miniaturization, and works in all-day and all-climate. As a key part of the radar system, antenna is required to be operated with high gain, narrow beamwidth, low sidelobe level, and compact in size. In this paper, a 77 GHz millimeter-wave patch antenna array is designed to meet requirements proposed by UAVs obstacle avoidance radar. The designed antenna array is able to provide gain of 31.08 dB with narrow 3-dB beamwidth (8.97° in azimuth and 11.66° in elevation). Moreover, it effectively decreases sidelobe level to -24.5 dB relative to main lobe and uses less radiation elements than regular two-dimensional planar array, which leads to a compact size.