Beam-Reconfigurable Multi-Antenna System with Beam-Combining Technology for UAV-to-Everything Communications

Abstract

This paper proposes a beam-reconfigurable antenna for unmanned aerial vehicles (UAVs) with wide beam coverage by applying beam-combining technology to multiple antennas with different beam patterns. The proposed multi-antenna system consists of a circular patch antenna and a low-profile printed meandered monopole antenna. For beam combining, a coplanar waveguide with ground (CPW-G) structure feeding network is proposed, and it consists of two input ports, a 90° hybrid coupler, a microstrip 90° phase delay line, and a single-pole double-throw (SPDT) switch. It performs the role of power distribution and phase adjustment, and synthesizes the broad-side beam of the monopole antenna and the end-fire beam of the patch antenna to form the directive broadside beams in four different directions. The proposed antenna system operates at 5–5.5 GHz which covers both UAV ground control frequencies (5.03–5.09 GHz) and UAV mission frequencies (5.091–5.150 GHz). The peak gain, total efficiency, and half-power beamwidth (HPBW) of the antenna system are approximately 5.8 dBi, 76%, 145° in the elevation plane, and 360° in the azimuth plane respectively. Its electrical size and weight are λ 0 × λ 0 × 0.21 λ 0 at 5.09 GHz and 19.2 g, respectively.

Printed Dipole Antenna Array With Reconfigurable Feeding Network for Wide Elevation Angle of U2X Communications

“…In 2012, through the World Radio Communication Conference (WRC-12) under the International Telecommunication Union (ITU), the frequency band for wireless communication of UAVs (5.03 to 5.091 GHz) and the frequency band for missions (5.091 to 5.15 GHz) has been assigned. Accordingly, studies have been conducted on high-gain antennas with low air resistance operating in the 5 GHz band [18]- [20].…”

“…[19] produced an antenna with a high gain and wide elevation angle using Yagi-Uda dipole antenna array. [20] achieved a high gain and wide elevation angles by implementing a relatively low-profile antenna by using a meander monopole and a circular patch antenna. Previous studies on antennas for UAV communications operating in the 5 GHz band were also conducted.…”

Horizontal Polarized DC Grounded Omnidirectional Antenna for UAV Ground Control Station

“…The use of unmanned aerial vehicles (UAVs) is rapidly expanding to commercial, scientific, agricultural, and military applications [ 4 ]. To overcome the difficulty of finding the exact location of mobile UAVs from ground control stations (GCS), omnidirectional antennas are utilized to resolve acquisition and pointing complications [ 5 , 6 , 7 , 8 , 9 , 10 ]. It has been proven that using horizontally polarized antennas can achieve a 10 dB improvement in terms of system gain as compared to vertically polarized antennas [ 11 ].…”