U.S. defense contractors are putting counter-drone systems through live electromagnetic warfare (EW) stress tests, and the demonstrations are highlighting how the military may need to defend against swarm attacks in jammed, contested spectrum conditions. Over the spring and summer of 2025, two separate demonstration campaigns tested whether American-built systems can detect, track, and neutralize hostile drones even when adversaries flood the radio spectrum with jamming signals. The stakes are concrete: drone swarms have already reshaped combat in Ukraine, and the Pentagon wants fielded solutions, not laboratory prototypes.
Pentagon Tests Nine Systems Under Simulated Jamming
The Joint Counter-small Unmanned Aircraft Systems Office and the Army Rapid Capabilities and Critical Technologies Office ran their sixth industry demonstration from April 7 to 25, 2025, at Yuma Proving Ground in Arizona. Eight companies brought nine systems to the desert range, where each was evaluated against multiple electromagnetic environment sets, including baseline, low-frequency, and high-frequency configurations, according to defense-industry reporting. Those different “EME sets” simulate the kind of contested spectrum conditions U.S. forces would face against a near-peer adversary that actively jams friendly communications and sensor links.
A June 4 report on the event described the scope of the demonstration. The deliberate use of varied electromagnetic conditions marks a shift from earlier counter-drone trials, which often tested detection and defeat capabilities in relatively clean spectrum. By layering jamming profiles onto the test environment, evaluators could measure whether a system that works in peacetime conditions degrades or fails entirely when an opponent turns on electronic attack. That distinction matters because many commercial counter-drone tools rely on radio-frequency detection or GPS denial, both of which become unreliable when the electromagnetic environment is saturated with interference.
The demonstration did not publicly release pass-fail scores for individual vendors. That gap limits outside analysis, but the structure of the test itself signals where Pentagon priorities are heading. Evaluators are no longer asking whether a system can stop a single drone on a clear day. They want to know whether it can still function when the airwaves are hostile, when multiple drones arrive simultaneously, and when the command-and-control network is under electronic assault.
Officials also emphasized interoperability and open architectures. In a dense battlespace, counter-drone radars, electro-optical cameras, jammers, and kinetic interceptors must share targeting data quickly enough to keep up with low, fast, and maneuverable threats. Testing nine distinct systems under common electromagnetic conditions gave the Joint Counter-small UAS Office insight into which designs can plug into a broader air-defense web and which remain standalone point solutions.
Epirus Defeats a 49-Drone Swarm With One Pulse
A separate demonstration later in 2025 put directed-energy hardware to a dramatic test. At Camp Atterbury, Indiana, Epirus fired its Leonidas high-power microwave system at a 49-drone swarm and, in a company press release, said it neutralized all 49 with a single pulse. Across the full live-fire event, 61 of 61 drones flown were defeated, according to the company. The demonstration took place the week of August 28, 2025, with U.S. military service representatives and international observers watching from the ground.
Epirus describes Leonidas as projecting a focused beam of microwave energy intended to disable drone electronics. Unlike kinetic interceptors or radio-frequency jammers, a high-power microwave weapon does not need to match the target’s communication frequency or track each drone individually. It blankets a cone-shaped area and disables anything electronic inside it. That approach sidesteps the core problem the Yuma tests were probing: if a drone swarm uses autonomous navigation and does not depend on a radio link, traditional jammers cannot stop it. A microwave pulse does not care whether the drone is GPS-guided, autonomously navigated, or manually piloted.
Epirus leadership described next steps that include integrating sensing, electronic warfare, and cyber warfare capabilities alongside the microwave effector. That ambition points toward a layered kill chain where detection, electronic attack, and directed energy all feed into a single platform rather than requiring separate vehicles and crews for each function. A truck-mounted system that can both locate and disable drones without handing off to another unit would simplify logistics and reduce the time between detection and engagement.
The Camp Atterbury event also underscored a key operational question: how many shots can a directed-energy system deliver before overheating, draining its power source, or requiring maintenance? Demonstrating 61 successful engagements suggests Leonidas can cycle rapidly enough for at least a short, intense fight. For commanders planning to defend an airfield or a forward operating base, that kind of sustained rate of fire may matter more than the spectacle of a one-pulse, 49-drone kill.
Why Electromagnetic Resilience Is the Real Bottleneck
Most public discussion of counter-drone technology focuses on the “defeat” side of the equation: how to knock a drone out of the sky. But the harder engineering problem is keeping the detection and tracking systems alive when an adversary is actively jamming them. A counter-drone radar that loses its picture the moment an enemy electronic warfare aircraft lights up is worse than useless because it creates a false sense of security.
The Yuma demonstration’s use of baseline, low-frequency, and high-frequency EME sets reflects Pentagon awareness of this vulnerability. In principle, systems that perform well in clean spectrum but degrade under jamming are the kinds of weaknesses this April trial structure is designed to reveal. The fact that the Joint Counter-small UAS Office chose to publicize the electromagnetic environment challenge, rather than just the number of drones shot down, suggests the office views EW resilience as the differentiator between vendors that are ready for contested operations and those that are not.
Designing for resilience means hardening receivers against overload, adding redundant communication paths, and building algorithms that can filter out deceptive signals. It also means accepting that no single sensor will be reliable all the time. Future counter-drone architectures are likely to fuse radar, passive RF detection, optical tracking, and even acoustic cues so that if one channel is jammed or spoofed, others can still provide a firing solution.
The Department of Homeland Security is wrestling with a similar challenge in the civilian domain. Under authority granted by 6 U.S.C. Section 124n, the DHS Science and Technology Directorate runs its own counter-UAS evaluations to protect airports, stadiums, and other critical infrastructure. While DHS scenarios focus on domestic threats and legal constraints, the technical question converges with the Pentagon’s: can a counter-drone system maintain effectiveness when the electromagnetic environment turns hostile, whether from intentional jamming or dense urban interference?
Non-Kinetic Weapons and the Cost Calculus
Directed-energy and electronic warfare solutions carry a financial argument that kinetic interceptors cannot match. A missile that costs tens of thousands of dollars to shoot down a drone worth a few hundred dollars is an unsustainable exchange ratio. A microwave pulse, by contrast, draws from a power supply. Once the hardware is fielded, each shot costs little more than the electricity it consumes, and magazines are limited by fuel and cooling capacity rather than by how many interceptors can be trucked to the front.
That cost advantage explains why the Pentagon is pursuing two complementary tracks of experimentation. The Yuma trials stress-tested a range of approaches, including electronic warfare jammers, radar-cued guns, and other non-kinetic tools, under realistic electromagnetic stress. The Camp Atterbury event, by contrast, showcased a single, high-end directed-energy system against a concentrated swarm. Together, they sketch the outline of a future force in which inexpensive, high-volume threats are met by equally scalable defenses.
Still, non-kinetic options are not a cure-all. High-power microwave systems must manage safety concerns, fratricide risks to friendly electronics, and line-of-sight limitations. Jammers can interfere with friendly communications if not carefully coordinated. And both can struggle against hardened or shielded drones. For the near term, commanders are likely to field layered defenses that mix kinetic interceptors, electronic attack, and directed energy, tailoring the response to the threat and the surrounding environment.
What is changing, and quickly, is the threshold for what counts as “good enough.” A counter-drone system that cannot survive in a jammed spectrum, or that can only affordably defeat a handful of targets before running out of missiles, no longer meets the bar. The latest demonstrations suggest that U.S. defense planners are moving past isolated prototypes and toward integrated, resilient architectures built for a world where swarms, jamming, and directed energy are all part of the same fight.
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*This article was researched with the help of AI, with human editors creating the final content.
