DARPA Aims to Wirelessly Charge Drones Mid-Flight with Power-Beaming

DARPA has boosted funding for far-field wireless power transfer, or power-beaming, for in-flight drone charging. This eliminates the need for mission interruptions for recharging or battery replacement, potentially saving critical missions.

Dr. Ifana Mahbub, an assistant professor of electrical and computer engineering at The University of Texas, received DARPA’s Young Faculty Award in 2021, granting $500,000 over two years for her project. She has now been awarded an additional $250,000 fellowship to further develop power-beaming technology.

Wireless Charging Technology

You may know about wireless charging in cell phones, using near-field technology and low-frequency electromagnetic waves over short distances.

Though seemingly magical, wireless charging operates on a simple principle: a charging unit generates an electromagnetic field via a coil, while the receiving end (like your phone’s coil) captures these waves to create an electrical current, charging the battery.

Mahbub and her team are exploring far-field technology to extend the range over which electromagnetic waves can be transmitted.

However, their aim is to completely eliminate the necessity for drones to return to base (RTB) for a battery swap or recharging, which can consume valuable time and resources, and may even compromise the ongoing mission. Instead of recalling a UAV, why not charge its battery while it remains airborne?

One significant challenge for Mahbub is maintaining the integrity of electromagnetic beams over extensive distances to prevent power loss.

Phased-Array Antennas for Precision Charging

To address this, Mahbub has devised an ingenious solution involving phased-array antennas, which consist of a network of transmitters and smaller antennas to precisely guide the electromagnetic beam along a designated trajectory. Her technology leverages real-time UAV telemetry to ensure continuous line-of-sight connectivity, thereby maximizing charging efficiency.

“The signal can propagate in unintended directions,” explains Mahbub. “Our objective is to manipulate the waveform to reduce path loss.”

Military drones, such as Medium Altitude, Long Endurance (MALE) UAVs, are engineered to reach altitudes of up to 25,000 ft (7,620 m), while High Altitude, Long Endurance (HALE) drones frequently operate at a ceiling of 50,000 ft (15,240 m). Tactical drones typically fly within the range of 2,000 ft (610 m) to 5,000 ft (1,524 m).

Applications Beyond Drones

This technology has numerous potential applications. Imagine electric cars being charged while traveling on the highway. Mahbub is developing safe, low-frequency wireless charging technology, potentially capable of charging medical implants in humans, approved by the FCC.

While the concept of transmitting electromagnetic waves to charge a small aircraft might seem daunting, similar methods have been employed for years.

To conclude, Radio broadcasting, television broadcasting, cell phone service, radar, Wi-Fi, and even GPS all rely on electromagnetic waves.

However, it would likely be unwise to stand between the transmitter and the drone during the charging process.

Read the original article on: New Atlas

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