Microwave Wireless Power Supply System to a Micro Aerial Vehicle

Abstract

: A microwave power beaming system was developed to realize wireless power supply to a Micro Aerial Vehicle. This system consists of transmitting, tracking, and receiving systems. In the transmitting system, a 5.8 GHz microwave beam was irradiated from an active phased array antenna. Transmitting power was 4 W and the beam divergence angle was 9 deg. In the tracking system, a 2.45 GHz pilot signal was detected by a two-dimensional tracking antenna and the position was deduced though the software retro-directive function. The maximum tracking error was 1.97 deg in the azimuth direction and 1.79 deg in the radial direction. In the receiving system, a light-weight flexible patch rectenna was developed using felt pad as substrate. The maximum rectenna efficiency of 45.3% was obtained with a 100 Ω road at 63 mW input power. By integrating these systems, auto-tracking wireless power supply was demonstrated to a MAV model circling at the altitude of 1,500 mm. As a result, a motor was kept rotated. Received power was 24.3 mW at maximum and 17.6 mW on average and the total transmission efficiency was estimated at 0.60%.

Wireless Power Transfer to a Microaerial Vehicle with a Microwave Active Phased Array

“…This value is smaller than the average of the axial ratio of the SRA elements, 0.575 dB. Furthermore, it is also high compared with that of the non-SRA system described in an earlier report [8]. Moreover, it shows that the introduction of SRA improves the axial ratio.…”