Research And Implementation Of Ultra-wideband Array Antenna In UAV Communication

As an important component of UAV communication system,the performance of antenna technology directly affects the information transmission reliability of the communication system.As traditional narrowband antennas cannot meet the current needs of UAV communication,ultrawideband array antennas are widely used in order to improve communication efficiency and expand system capacity.Therefore,this paper carries out research on ultra-wideband array antennas in UAV communication,designs three different types of antennas,and verifies their performance through simulation or actual measurement results.The main work of the paper is as follows:1.A 1×8 log-periodic line array antenna with low VSWR and wide angle beam scan was designed and implemented.Firstly,a log-periodic antenna unit with an operating frequency of 2GHz～6GHz is designed,and its VSWR in the frequency band is less than 2,and the gain in the operating frequency range is greater than 4d Bi.Then the linear array test results of the antenna unit show that the VSWR of the array antenna is less than 2 in the impedance bandwidth of 2GHz～6GHz,and the minimum gain of the 8 beams in the-45°～45° beam scan range is greater than 9d Bi.The minimum gain of the8 beams in the-45°～45° beam scan range is greater than 9d Bi,which is suitable for carrying on the UAV platform to achieve broadband air-to-ground communication.2.A Vivaldi antenna unit and an array antenna composed of it are designed and implemented.Firstly,a Vivaldi antenna unit operating in the frequency band of 0.8GHz～2.4GHz was designed,and the effects of different gradient curvatures and antenna heights on the VSWR and gain of the antenna were analysed.Then,the Vivaldi antenna units were assembled and the simulation results showed that the VSWR of the ultra-wideband 1×3 Vivaldi line polarisation array was less than 3 in the frequency band range of 0.8GHz～2.4GHz,and the minimum gain of all four beams in the wide angle beam scan range of-45°～45° was greater than 4.8d Bi.3.A 1×3 ultra-wideband biconical line polarisation array antenna realising wide-angle beam scanning was designed and fabricated,which can be applied to an unmanned aircraft to achieve airground wideband communication.Due to the restricted installation size of the UAV platform,lowprofile and miniaturisation features are achieved by replacing the conventional tapered array with an ellipsoidal array and cutting the external profile of the ellipsoidal oscillator so that it can be installed in a space of 250 mm × 130 mm × 90 mm.Simulation results show that the voltage VSWR of the array antenna is less than 2.5 in the frequency band range of 0.8～2.4GHz,the isolation between units is greater than-10 d B,and the minimum gain of all four beams in the ±45° beam scan range is more than 2d Bi,which meets the practical application requirements.