The growing use of drones in combat has been described as "the most concerning tactical development" since IEDs became prevalent in Iraq. Small, inexpensive UAVs are already used for surveillance, disruption of airspace and dropping small explosives, but in the near future swarms of robot vehicles could become even more dangerous – both on the battlefield and around civilian spaces like airports or sports grounds.


To address the issue, military researchers and arms manufacturers are developing directed energy weapons with the power to disable drones using lasers, particle beams, radio frequency waves and more. One of the latest is called Leonidas, created by US start-up Epirus. It uses high-powered microwaves (HPM) to overwhelm drones' onboard electronics.

The system (a prototype of which is reflected above) uses Gallium Nitride semiconductors to produce extreme levels of power density while firing the HPM. Operators can narrow the beam to target individual drones or take down multiple threats across a wider field. Epirus staged a demonstration event for government officials earlier this year and the device disabled all 66 drones sent to swarm around it.

"Our state-of-the-art digital beamforming capabilities allows operators to safely direct the HPM beam on target to disable enemy threats and nothing else," says Leigh Madden, Epirus CEO. "These capabilities were on full display at a recent customer event where Leonidas executed multiple precision strikes, disabling an enemy target and leaving a blue force drone untouched."

Unlike some directed energy weapons, Leonidas is small enough to mount on a truck or boat, and its rapid-fire capabilities make it practical on kinetic battlefields. Epirus is also in the late stages of development for even more compact and portable systems, and the technology could eventually lead to some kind of microwave gun.

"Leonidas has revolutionised what's known as the Size, Weight and Power (SWaP) factor and is dramatically smaller in size than competitive systems," says Madden. "As we continue to drive innovation, our systems will decrease in size and increase in power density."

Anti-drone weapons may also be required beyond the battlefield. As UAVs become cheaper and more prevalent, so too does their potential for harm in civilian spaces. In December 2018, London's Gatwick Airport closed for two days after mysterious (and never-found) drones were reported in the skies around the runways. Fearing a collision could take down a passenger aircraft, the military was deployed and more than 1,000 flights were cancelled.

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Other identified threats include recreational drones flying too close to rescue helicopters, attacks in civilian spaces, reconnaissance of nuclear sites, invasion of privacy and even as a distraction to aid criminals.

Madden says that while Epirus is currently focused on work with the US Department of Defense, it is also in discussions to "bring new products to market and support additional use cases across industries."

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In recent years, directed energy weapons have also been reportedly used against human targets. In 2017, personnel at the US embassy in Cuba complained of suddenly hearing noises and pressure in their ears, followed by symptoms such as headaches, vertigo, dizziness and loss of cognitive functions. Since labelled Havana Syndrome, it has been attributed to some kind of directed energy weapon.

Similar reports have suggested the Chinese military used a microwave weapon against Indian troops in 2020 and that a similar device may have targeted US civilians in Washington DC the same year. While none of these reports have been definitively confirmed, a working hypothesis is that beams of high-frequency electromagnetic radiation are used to heat the water in a human target’s skin, causing pain and discomfort. The results are not thought to be long-lasting, but it's potentially an effective way to incapacitate a target without the use of lethal force.

"These reports are certainly concerning for everyone here at Epirus, but it’s important to make clear that what we are doing with directed energy is entirely different from the alleged microwave attacks on humans," says Madden. "Epirus is harnessing the power of directed energy to bolster national security, not create new threats.

"We have developed modes of operation and waveforms that operate differently from other directed energy systems to ensure that Epirus’ products do not cause unintended harm to operators and are, indeed, human safe.


"Our products do not contain nuclear components, nor do they produce harmful radiation. The radiation produced is similar to that of cellular phone waves or your countertop microwave unit."

3 More Ways to Down a Drone

DroneGun MKIII

This handheld, pistol-shaped device fires radio frequency waves to jam the signal between a drone and its operator. With a range of 500m, the gun, developed by DroneShield in Australia, is one of the most portable anti-drone technologies in the world. 

Trained eagles

In the wild, birds of prey have been known to randomly attack drones that they presumably mistook for food or competition. Now, Dutch police are signing up feathered crimefighters by training eagles to attack drones that stray too close to airports or high-security events.


Designed to guard airports and prisons as well as military and government buildings, this patrol drone intercepts targets mid-air and hovers nearby. It then fires a large net to trap incoming drones and bring them to the ground.


A former deputy editor at Science Focus, Ian once undertook a scientific ranking of the UK's best rollercoasters on behalf of the magazine. He is now a freelance writer, which is frankly a lot less fun.