When Hawthorne, Calif.–based startup Epirus decided to test a new electronic weapon last winter, it filed an application with the Federal Communications Commission (FCC). It wanted to test its high-power microwave device in the California desert east of Palm Springs, Calif., about three miles from a small airport and the busy I-10 interstate.
The unnamed prototype would be operated intermittently with an effective radiated power of 270 megawatts—thousands of times higher than the strongest FM radio stations, and in the same ballpark as controversial experiments that produce artificial aurorae—and have a range of 300 meters.
Microwave energy induces a current on the surface of metal objects. Any electronic device in range of powerful microwaves will experience heat and arcing on its circuits, rapidly (and likely permanently) disabling it.
Pesky drones around sensitive areas like airports, prisons, borders, and sporting events have created an instant market for antidrone and microwave weapons, once the preserve of the military.
Microwave weapons that target humans have also been developed, with a recent National Academies report blaming microwave weapons for mysterious illnesses in U.S. embassies around the world.
Epirus is named after a magical bow with infinite arrows wielded by the Greek hero Theseus. (Coincidentally, it is also the name of the Greek island family home of ex–Director of Central Intelligence George Tenet, whose son John cofounded the company.)
The solid-state phased array device, wrote Epirus, would be a "critical component of several solutions Epirus plans to provide for existing and future government customers, including vehicle/vessel stop, counter-electronics, and counter-communications solutions."
Prototype of a Leonidas Pod microwave weapon mounted on a drone.Epirus
Epirus offers a trailer-size weapon called Leonidas that could be the device in question. It also has a smaller Pod weapon, light and compact enough to mount on a drone that can "disable a wide range of electronic threats." The company claims it has developed "artificial intelligence–enabled gallium nitride (GaN) semiconductors" to produce "extreme" levels of power density.
"A ray gun that can fry a drone's electronics at hundreds of meters sounds like something Tony Stark would invent," says Todd Humphreys, director of the Radionavigation Lab at the University of Texas at Austin. Humphreys is also concerned that the system, as described in the FCC application, could produce interference at frequencies used by GPS and Galileo navigation services.
Epirus told IEEE Spectrum that this would not be the case, and Dr. Edl Schamiloglu, an expert in high-power microwaves at the University of New Mexico, agreed that any disruption to distant aircraft would likely only be momentary.
"Generally speaking, these systems are also relatively harmless to humans because there's hardly any thermal energy," said Schamiloglu. "But the Epirus system does seem very viable for a localized defense of a commercial facility, like Yankee Stadium."
The FCC, however, did not let the experiment proceed. "You are advised that the Commission is unable to grant your application for the facilities requested," it wrote back to Epirus's CTO in October. "The FCC is not authorized to approve systems that cause interference or jamming. These systems may only be approved by NTIA for military or other law enforcement type systems."
The National Telecommunications and Information Administration is the regulator that oversees military and federal spectrum experiments and allocations.
Epirus is far from the only company eager to test electronic weapons. Anduril Industries, another California mil-tech startup, sought permission from the FCC to test an antidrone system in January, again in Southern California. Its technology is a scalpel to Epirus's hammer, generating signals to interrupt a drone's remote control rather than blast it out of the sky with microwaves. Anduril claimed its system could down drones up to 2 kilometers away in any direction.
Andruril Industries Anvil sUAS.Andruril
"The test device is designed to disrupt…an intrusive drone…by transmitting in the same way as the FCC-authorized device, adding noise in a very targeted fashion with effects limited to the target device and causing the target device to land or return to a predetermined location," wrote an Anduril electrical engineer to the FCC.
The FCC denied the request with a virtually identical response: "The FCC is not authorized to approve testing and operation of this type of system that will disrupt the control channel of a UAV. These systems can only be authorized by NTIA for military or federal agency users."
That didn't stop Anduril from filing similar requests again in mid-February and early April, nor dissuade Alion Science and Technology and DroneShieldfrom seeking permission for their own interference-based antidrone tests. Three of these applications were for demonstrations at the U.S. Navy's Trident Spectre event at a military base in Virginia later this month.
Trident Spectre is an annual exercise organized by the Navy to showcase new technologies for its intelligence and special operations units.
DroneShield wanted to demonstrate the DroneGun MKIII, a "pistol-style" counterdrone disruptor, while Alion admitted to the FCC that it would be "demonstrating a variety of electronic attacks." All three applications were swiftly denied. A 2011 document written for the Joint Chiefs of Staff states that electronic attack testing is not permitted outside of dedicated Department of Defense electronic warfare ranges.
None of the four companies responded to questions about their testing, nor told Spectrum whether the NTIA had subsequently approved their operations within those limits. Because the NTIA does not make details of tests public, it is impossible to know their frequency or scale.
However, it is possible that these—and many other—electronic-weapons experiments are now proceeding quietly, in collaboration with the NTIA and the U.S. military. Anduril has publicly linked its antidrone tests to the Pentagon's Defense Intelligence Unit, while Epirus's weapon was developed with Navy funding. All four companies have received government contracts.
Nor is the military the only intended customer for such systems. Judging from the company's website, Epirus is marketing its microwave weapons to sports stadiums and concert venues—and it envisages police forces deploying Epirus technology to bring down hostile drones.
As such systems mature, there is the potential for microwave and other electronic weapons to be tested and even deployed with little advance notice to the general public. And the next time your drone or car or phone suddenly stops working, perhaps microwaves will get the blame.
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Mark Harris is an investigative science and technology reporter based in Seattle, with a particular interest in robotics, transportation, green technologies, and medical devices. He’s on Twitter at @meharris and email at mark(at)meharris(dot)com. Email or DM for Signal number for sensitive/encrypted messaging.