In a U.S. Department of Defense demonstration, a single electromagnetic pulse from Epirus's Leonidas system downed 49 drones simultaneously. The system then finished the job: 61 drones engaged, 61 destroyed — a 100% kill rate. No interceptor missile expended. No reload. The only consumable was electricity.

That result encapsulates the core thesis of high-power microwave (HPM) technology: where kinetic interceptors fight one-to-one and directed-energy lasers track one target at a time, a sufficiently powerful microwave burst can defeat an entire swarm in a single engagement. Whether Leonidas delivers on that thesis at scale — against hardened drones, in contested electromagnetic environments, across the Indo-Pacific — is what the U.S. Army and Marine Corps are spending the next several years determining.

Why GaN Changes the Calculus

High-power microwave weapons are not new. Legacy systems relied on vacuum tubes — magnetrons, klystrons, gyrotrons — to generate microwave energy. These components are bulky, thermally expensive, and slow to bring online. Epirus's approach strips out the tubes entirely, replacing them with arrays of Gallium Nitride (GaN) semiconductor amplifier modules. GaN has dominated military radar and electronic warfare hardware for over a decade, valued for its high electron mobility and breakdown voltage. Applied to an HPM weapon, it allows Leonidas to operate at low voltages, start up or shut down in minutes rather than hours, and eliminate the coolants that make traditional directed-energy systems logistically burdensome in the field.

The architecture is software-defined in a meaningful sense. Epirus calls the control layer SmartPower — an AI-enabled system that monitors and optimizes power delivery against target electronics in real time. Paired with a digitally beamformed antenna, Leonidas concentrates energy on the engagement zone while protecting friendly forces from the HPM output. The beam width is wide by design: the one-to-many defeat model depends on covering a volume of airspace rather than dwelling on a single aimpoint, which is the structural advantage over both missile interceptors and laser systems.

Logistics matter at least as much as physics. Line-replaceable amplifier modules can be swapped by troops in the field in less than eight minutes. There is no ammunition supply chain, no resupply convoy to protect. The system can engage continuously as long as power is available — a significant advantage when defending a fixed site from repeated swarm probes.

The IFPC-HPM Program: Contract, Delivery, and a Tropical Live-Fire

In December 2022, the U.S. Army Rapid Capabilities and Critical Technologies Office awarded Epirus the Indirect Fire Protection Capability – High-Power Microwave contract after a competitive evaluation. The full prototyping contract, publicly announced in January 2023, was valued at $66.1 million.

"Time and time again, we've seen that current air defense systems are ill-equipped to tackle the threat of autonomous drone swarms." — Ken Bedingfield, CEO, Epirus, January 2023

IFPC-HPM is designed to protect fixed and semi-fixed sites as part of the Army's layered air defense architecture. The system integrates an HPM source, a power and thermal subsystem, and an antenna subsystem, all interoperable with battle management command, control, and communications software. Epirus delivered the first prototype to the Army on November 1, 2023, after government acceptance testing at a Nevada test site. A second prototype followed by the end of December 2023, and the full four-system platoon was completed by May 2024.

The 1st Multi-Domain Task Force became the first unit to field the systems. The most significant operational test to date came on April 28, 2025, when the 1st MDTF conducted live-fire tests at Naval Station Leovigildo Gantioqui in the Philippines during exercise Balikatan 2025 — the first Indo-Pacific deployment and the first tropical-environment test of the system. The Philippine Air Force 960th Air and Missile Defense Group participated as subject matter experts in the exercise.

"During this test, we were able to demonstrate that we can successfully defeat drone swarms in a tropical environment using layered effects," said Capt. Bray McCollum, battery commander of the 1-51 ADA battalion.

In July 2025, the Army RCCTO awarded Epirus a follow-on contract of $43,551,060 for two Generation II systems, spare parts, support equipment, and test events. Generation II offers more than double the maximum effective range of Generation I, a projected 30% increase in power output, high-density batteries for extended operating times, extra-long pulse widths for maximized energy output, a high-duty burst mode for rapid multi-target engagement, and advanced waveform and polarization techniques. The performance delta reflects direct feedback from real-world drone threat evolution.

The Marine Corps Track: ExDECS and the Expeditionary Form Factor

The Marine Corps pursued a parallel acquisition path through the Office of Naval Research. Under the PEGASUS program — Preliminary Evaluation of Ground-based Anti-Swarm UAS System — ONR contracted Epirus for the ExDECS (Expeditionary Directed Energy Counter-Swarm) system, with a follow-on award in September 2024. Epirus delivered the first ExDECS prototype to Naval Surface Warfare Center Dahlgren Division in early 2025 after completing Factory and Government Acceptance Testing.

ExDECS is derived from the Leonidas Expeditionary platform, trailer-mounted for Marine Corps Low Altitude Air Defense and Ground Based Air Defense missions. The cost per engagement is approximately five cents per drone — a figure that matters when an adversary can field commodity fixed-wing or multirotor UAVs for a few hundred dollars apiece. "Drone warfare is changing the fight — fast. Systems like ExDECS give Marines a decisive advantage by neutralizing multiple electronic threats at once," said Andy Lowery, CEO of Epirus.

Epirus has also developed the Leonidas Pod, a compact variant designed for aerial or dismounted use in drone-vs-drone counter-swarm operations. A third-generation Leonidas variant adds a 360-degree mechanical gimbal for full azimuth coverage. Integration partners include Anduril Industries, whose Lattice AI-driven command and control software connects Leonidas into a broader sensor-to-shooter architecture, alongside Northrop Grumman for C-UAS systems-of-systems and General Dynamics Land Systems, which completed Stryker vehicle integration testing in October 2022.

Why It Matters

HPM fills a specific gap in the layered air defense stack — the swarm problem that neither SHORAD missiles nor laser systems can economically solve. A Patriot battery cannot engage 49 targets simultaneously. A laser requires dwell time measured in seconds per target, which collapses against a coordinated wave. An HPM burst wide-areas the engagement zone in a single shot, at a cost per engagement that does not erode economic advantage when the threat is cheap and numerous.

The honest limits are real: effective range is classified and shorter than high-energy lasers; line-of-sight is required; adversaries can harden drone electronics or shift to fiber-optic guidance to defeat RF-based intercepts; and sustained operation demands a reliable power supply that may not be available in every expeditionary scenario. Tactics, techniques, and procedures are still being developed — as Epirus itself noted, the IFPC-HPM platoon will undergo capabilities and limitations testing "to develop tactics, techniques and procedures for how the capability will be used in theater as part of a layered defense posture for the counter-UAS mission."

What Balikatan 2025 demonstrated is that the technology transfers to demanding operating environments — tropical humidity, unfamiliar logistics chains, coalition interoperability requirements. The Generation II contract signals that the Army sees enough operational promise to push for greater range and endurance rather than step back. Where HPM ultimately lands in the final layered air defense architecture depends on a threat environment that is itself moving faster than any single acquisition cycle.

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