Phased Array for UAV Communications at 5.5 GHz

This letter presents the design and manufacturing of a phased array at 5.5-GHz band. The antenna application is the communications with unmanned aerial vehicles (UAVs) in a wildfire. The antenna is controlled through a WiMAX station. The vertical radiation pattern is a shaped beam. This shaped beam has the maximum at broadside and a smooth gain decay in positive θ. This way, the differences in the free-space losses of the UAVs are compensated. The antenna is steered in the horizontal plane through phase shifters. It also includes amplifiers and digital attenuators to calibrate the antenna performance. A calibration method is also proposed in the letter.