UAV Communication Antenna Array with Wide Coverage Multi-beam 3 × 2 Switched Beamforming Network

Abstract

In this paper, unmanned aerial vehicle (UAV) communication antenna array with wide coverage multi-beam $3 \times2$ switched beamforming network is presented. It consists of two dipole antennas and metallic reflector included feeding network using microstrip line. Dipole antennas are linearly located along $y -$axis that the separation distance is $1/4 \lambda_{0}\,(\lambda_{0}$ is a wavelength at 5 GHz). The proposed antenna is operating from 5.03 GHz to 5.15 GHz of the UAV communication frequency. To reduce the back radiation and enhance the front and side radiation, a metallic reflector is included in this configuration. In addition, It is longer than $1/3\lambda_{0}$ away from radiators with a feeding network. The proposed feeding network is made up of a single-pole triplethrow (SP3T) switch, 2-way power divider, two single-pole double-throw (SPDT) switches, and one 90° hybrid coupler. This circuit divides the power in half and distributes it to array antennas with three different phase shifts. Measured peak gains with respect to each beamforming modes are approximately 4.36, 3.5, and 3.57 dBi, respectively. Halfpower beam width (HPBW) of the proposed antenna is about 200° and Its size is $0.8 \lambda_{0}\, \times 0.67 \lambda_{0}\, \times 0.35 \lambda_{0}$.