Electric Sky, Inc. (El-Sky) announced it has begun building the world’s first “Whisper Beam” transmitter for wirelessly powering in-flight UAVs (unhumanned aerial vehicles), with funding from the U.S. Defense Advanced Research Projects Agency (DARPA).
Past wireless power for UAVs used lasers or microwaves, which start strong but get weaker as they travel. Whisper Beam technology does the opposite, starting weak and getting stronger near the receiver.
“Whisper Beam technology is the electromagnetic equivalent of a whispering gallery,” said Robert Millman, CEO of Electric Sky. “In a whispering gallery a single listener across the room can hear the speaker but no one else can, not even people standing directly between the speaker and listener. The sound is too weak for them to hear.”
With Whisper Beam technology, radio waves self-focus at the receiver, enabling the UAV to draw kilowatts of power in all weather. The waves are weak everywhere else, even directly between transmitter and UAV.
“It’s a myth that long-distance power transmission is impossible, it’s just never been economical,” Whisper-Beam inventor Jeff Greason noted. “This new method reduces the cost of the ground transmitter and the size of the vehicle’s onboard receiver.”
“Any type of electric aircraft can draw power while in flight – battery-electric, hydrogen fuel cell, and hybrid,“ Greason added. “Whisper Beam technology is particularly helpful in the power-hungry phases of takeoff and climb, enabling vehicle designers to meet other requirements to extend range, enhance flight safety, reduce peak loads on batteries, and shorten ground turnaround times.”
“Electric flight is more economical and environmentally-friendly than fossil fuels; our goal is to add the range it needs to out-compete fossils,” Millman added.
For DARPA, El-Sky will explore adapting the new wireless architecture to power a swarm of UAVs. Working under DARPA’s Small Business Innovation Research (SBIR) program, El-Sky will build and test a lab-bench demonstrator at short distances. These experiments will supply data needed to upgrade to higher power and longer distances, then adapt the transmitter to follow UAVs across the sky.