There is widespread adoption of drones for many tasks including search and rescue operations, surveillance, and delivery of commercial and medical supplies. However, there is one major drawback that always seems to be limiting the use of drones. This is their inability to stay airborne long enough. Because of their size and weight requirements drones typically have small battery packs. This means that the drones can only remain airborne for about 20-30 minutes which is often insufficient for most uses. In most cases, drone pilots are forced to ground the drone for a recharge or change of batteries.

Researchers from Queen’s University in Belfast, UK are developing some technology that could solve this problem. The researchers are looking into using microwave beams from the ground to power up airborne drones enabling them to continue flying for much longer flight times. The researchers are developing what they call RF-DC technology that will wirelessly transfer up to 200watts over distances of around 30m according to the project leader, Dr. Neil Buchanan.

As part of this project, Dr. Buchanan and his team will develop new wireless power receivers and transmitters. According to Neil, the system will send microwaves the same way a laser beam is sent. Which means it will need to be focused into one fine beam. For the transmitter, the team is investigating the application of a retro directive antenna which can direct a microwave beam automatically towards a target. The antenna is designed specially to send energy towards the drone. With such a system already in use in other fields like satellite communication, Dr. Buchanan feels they can successfully apply the technology in wireless power to drones in flight.

Aerospace engineers will be tasked with making sure the drones can still fly even when fitted with a wireless power receiver. When the project comes to an end, the researchers plan to carry out a lab demonstration of a vertical takeoff and landing, high efficiency microwave WPT, and continuous flight by an unmanned aerial vehicle powered by the system. In addition to powering drones, this technology could also be scaled up to power larger aircraft, and many other applications.