Novel Pattern-diverse Millimeter-wave Antenna with Broadband, High-gain, Enhanced-coverage for Energy-Efficient Unmanned Aerial Vehicle

In this paper, a novel pattern-diverse technique to enhance the coverage of the broadband high-gain millimeter-wave (mmW) antenna is proposed for Unmanned Aerial Vehicle (UAV) communications. It overcomes the limited coverage of a mmW antenna array, and the low radiation efficiency of a multi-beam mmW antenna array. This technique enables antenna to radiate two isolated beams with different tilted angles, which can effectively increase the UAV coverage without enlarging the antenna size or degrading radiation efficiency. For demonstration, an 88 antenna array is designed with the tilted beams of 11 and 23 for the coverage from 6 to 28. Measured results indicate two beams have 40 dB isolation, 15.2% impedance bandwidth, up to 21.7 dB stable gain, and up to 74.2% radiation efficiency. Antenna coverage could be further enhanced by arraying the proposed antennas in a flat structure. Example is given to radiate 18 beams covering 28 seamless 2D plane over 57-64 GHz. The size of the proposed array is smaller than that of a standard A4 page, which is suitable for UAV-mounted mobile base station (MBS).