Large-Scale Sequentially-Fed Array Antenna Radiating Flat-Top Beam for Microwave Power Transmission to Drones

Power beaming is one of the core technologies for microwave power transmission (MPT) systems. Effective plane-to-plane requires not only high point-to-point efficiency but also appropriately-shaped beam to extract best performance receivers (rectennas). Flat-top plays an important role in drones where output dc from rectennas should be maximized drive motors. It challenging develop a large-scale flat-top-beam array with appropriate distribution circuits. Sequential required suppress axial ratio on receiving plane. In this paper, we proposed simplified effective way create sequential flat-top at C-band. The series feed and block-oriented were adopted keep circuit design fabrication simple while obtaining sufficient good A 196-element phased microstrip antennas was developed by subdividing whole into four 49-element blocks simplicity implementation array. between transmitting ports 50.6 % simulations 32.0 measurements. measured beam, transmitted uniformly concentrated within plane successfully suppressed less than 3 dB most area. flight test microwave-powered drone conducted micro-drone flew seven minutes wireless power.