Microwaving Drones

Welcome back all…and thanks for being here.

This week, I’m taking a look beyond companies and nation-states to understand the technology underpinning their defensive efforts and enterprises.

The array of products on the market can easily feel bewildering. That’s especially true for someone like me, who is new to the industry.

However, a lot of it is underpinned either by a few new capabilities, or repurposed and upgraded existing ones, being rapidly and widely adopted.

First under the microscope is the use of high-powered microwaves, and the role they are coming to play as a cost-effective defensive measure against the threat of the drone.

One of the cheapest weapons on the modern battlefield is a small drone. A commercial quadcopter fitted with explosives costs a few hundred dollars.

The weapons traditionally used to shoot aircraft down sit at the other extreme, with interceptor missiles priced in the hundreds of thousands, sometimes millions.

That mismatch keeps air-defense planners awake. 

Against a single drone, trading a million-dollar missile for a few hundred dollars of quadcopter is bad value. 

Against a swarm, with dozens or hundreds arriving at once, it’s simply unaffordable.

You run out of expensive missiles long before your opponent runs out of cheap drones.

Jamming is the obvious cheaper answer, and for a while it worked: block the radio link between a drone and its pilot, and down it comes.

But the war in Ukraine has already produced a countermeasure. Fiber-optic drones trail a cable that carries their control signal, meaning no radio link to jam. A U.S. Army assessment last year called them “extremely difficult to detect and target.”

What every drone still has in common, jammable or not, is electronics. And that’s the opening a different kind of weapon is built to exploit.

A high-power microwave (HPM) weapon doesn’t fire a shell or shoot a laser. It stores up electrical energy and releases it as an intense pulse of microwaves, radiated from an antenna across a cone of open sky.

Those microwaves find their way into a target’s electronics by two routes. 

The “front door” is the set of antennas and sensors a drone uses to receive signals. That is to say, the openings designed to let energy in. 

The “back door” is everything else: the seams in a casing, the gaps around a panel, the wiring that threads through the airframe and acts like an unintended antenna.

Once the energy is inside, the effect scales with its strength. A modest dose scrambles the electronics and the drone loses control. A stronger one corrupts them. Hit it with enough and you can burn out the chips for good. 

Three things make HPMs attractive against swarms of unmanned air systems: 

A gun fires one round at one target. A laser burns one drone at a time, and has to hold a precise aim on each for a second or more. Microwaves trade that precision for coverage, and against a wall of incoming drones, coverage is worth more.

Knocking drones out of the sky is the application drawing money and attention, but it isn’t the only one.

The same physics that kills a quadcopter’s flight controller works against most things that run on electronics. 

Militaries see HPM as a way to disable radars, communications nodes, command posts, even the seeker heads of incoming guided missiles — degrading an opponent’s systems without destroying anything physical.

That non-kinetic quality is part of the appeal. A microwave pulse leaves buildings and people untouched, which makes it usable in crowded settings where an explosion wouldn’t be. 

The U.S. Navy, which is funding its own HPM work, cites exactly these traits — speed-of-light engagement, a deep magazine, and broad coverage suited to congested environments — as the reasons it’s investing.

Turning the physics into a deployable weapon is the harder part, and it’s where a handful of companies now compete. 

Most visible in the counter-drone role may be Epirus, a California firm whose microwave system, Leonidas, has moved from demonstration to real military orders.

Older microwave weapons fired a single, ultra-short blast. Epirus builds its system from many small amplifiers working together, steered and tuned by software, and holds the pulse on the target for longer — an approach it brands “long-pulse.” 

The result is closer to a large radar than a cannon, and much more mobile.

The same technology can sit as a fixed emitter guarding a base or airfield, or ride on a ground vehicle to move with a convoy or a forward position. 

The U.S. Army and Marine Corps have both placed orders, the Marines’ version built around a vehicle mount, so the weapon can travel with the troops it protects rather than waiting back at base. 

The picture the buyers are painting is of a defensive layer that arrives on a truck and switches on wherever the drones are.

The company has also shown the capability against the hardest case (short of the battlefield). In late 2025 it demonstrated its system bringing down a fiber-optic drone by reaching past the control link and into the electronics directly.

And it has drawn serious backing to scale up, including a $250 million round in early 2025 aimed at moving Leonidas from prototype to production line.

For all the momentum, HPMs’ limits matter as much as its promise.

The first is range. A microwave beam weakens quickly as it spreads, so these are close-in weapons — effective from hundreds of meters to a few kilometers, with exact figures classified. They defend a site or a formation; they don’t project power across a whole theater of war.

The second is hardening of the intended target. The same openings that let energy in can be closed. Shielding, filtered cabling, and radiation-hardened chips all raise a target’s tolerance, and a well-protected drone may shrug off a dose that would kill a hobbyist quadcopter. As the threat adapts and evolves, the weapons designed to counter it have to keep pace.

The third is the double-edged nature of a broad beam. Energy sprayed across an area doesn’t distinguish between the enemy’s electronics and your own. Used carelessly, an HPM system can disable friendly radios, sensors, or vehicles nearby, constraining where and how it can be switched on.

There are other factors too. The systems are power-hungry and run hot, which makes shrinking them for mobile use a real engineering challenge. Weather and atmosphere sap the beam. 

And unlike an explosive missile strike, damage to a drone zapped by a microwave isn’t always obvious. So knowing whether a target was actually disabled can be hard. 

Much of the performance data, in any case, is either classified or supplied by the manufacturers themselves.

None of that has slowed the field down. The drone swarm looks like a permanent feature of modern war, and the arithmetic of stopping it with expensive conventional missiles won’t hold up forever.

HPM is among the most credible answers yet to that area-and-cost problem, as a way to meet cheap mass attacks with cheap defense.

It won’t replace guns, jammers, or interceptors. It’ll sit alongside them as one layer in a defense.

And it’s a layer arriving quickly. The science behind microwaves has been understood for decades.

What’s new is that the hardware is finally rugged, mounted, and rolling toward the front line.