Multi-Beam Switchable Antenna System for Range-Extended Unmanned Aerial Vehicle

This letter proposes a radiation pattern switchable antenna system used for range-extended unmanned aerial vehicle (UAV) applications. It consists of a RF switch and three different antennas: a directional antenna (Ant. 1), a reconfigurable antenna (Ant. 2) and an omnidirectional antenna (Ant. 3). Ant. 1 is mounted on the top of the UAV to deliver high gain along the boresight direction, while Ant. 2 is positioned on the bottom to produce six downward reconfigurable radiation patterns. During regular flight missions, the omnidirectional antenna (Ant. 3) is used. Its signal weakens when the UAV is flying at high altitudes directly overhead or in underground applications like deep well exploration, triggering the RF switch to activate either the directional (Ant. 1) or reconfigurable antenna (Ant. 2) for a more robust link. For demonstration, the antenna system is fabricated and installed in a UAV. It operates at 2.4 GHz Wi-Fi band and achieves eight switchable radiation patterns. The measured transmission distance and power consumption of the UAV verify its advantages such as energy conservation and flying range extension.