THOR Microwaves Drone Swarms

In recent years small drones have gone from being toys and photography tools to a deadly threat on the battlefield. Kamikaze drones have become especially prominent in the news due to their use in the war in Ukraine by both sides. While we haven’t seen coordinated swarms being actively employed on the modern battlefield, it’s likely only a matter of time, making drone swarm defense an active field of development in the industry.

The US Air Force Research Laboratory recently conducted tests and a demonstration of an anti-drone weapon that uses pulses of high-power microwave energy to fry the electronics of a swarm of drones. Named the Tactical High-power Operational Responder, or THOR  (presumably they picked the acronym first), it’s housed in a 20ft shipping container with large microwave antenna on top. The form factor is important because a weapon is only useful if it can reach the battlefield, and this can fit in the back of a C130.

THOR likely functions similarly to a shotgun, with a relatively large effective “beam.” This would have added advantages like frying multiple drones with one pulse and not needing pinpoint tracking and aiming tech required for projectile and laser-based weapons. Depending on its range and directivity, THOR might come with the downside of collateral damage to electronics close to its line of fire.

Drone swarms are of course the other side of this arms race, but fortunately they also have non-destructive uses like lights shows and perhaps even 3D printing.

Are Microwave Guns For Real?

Almost exactly one year ago, [Kreosan] published a video detailing an EM “weapon” built out of three magnetrons, some batteries, and a taser. It all seemed a bit too good to be true, so [Allen] decided to try and replicate the results for himself.

[Kreosan]’s original video was impressive, showing everything from home stereos to a humble moped exploding when in the presence of their powerful device. However, many of those watching the video doubted the footage. Most criticism centered around the nature of the power supply to the magnetron falling short of the usual 700-1000W seen in a microwave oven.

Initial testing with a single magnetron. This setup could light the bulb at a distance of a few centimeters.

[Allen] starts by experimenting with a single magnetron, successfully using it to light a compact fluorescent bulb at a range of a few centimeters. Scaling up to the full triple magnetron setup with a cardboard and foil feedhorn, [Allen] is, at best, able to crash a calculator at a distance of a few feet.

The microwaves cause no explosions, and the device doesn’t seem to have anywhere near the 50-foot range claimed by [Kreosan] for their device. [Allen] puts forth the theory that the explosions seen in the original footage are far more likely to be from small firecrackers rather than any electronic components dying from microwaves.

Overall it’s a solid attempt to recreate someone else’s work to verify the results, a cornerstone of science. We did bristle somewhat at the valiant 18650 being described as a “vape battery”, however. For more microwave goodness, check out this attempt to recreate the TSA’s body scanners.