Where THOR's microwave source is a vacuum-tube design inherited from decades-old radar and jamming technology, Leonidas is built from gallium-nitride (GaN) semiconductor amplifiers, the same solid-state chip technology that has replaced vacuum tubes in modern active electronically scanned array (AESA) radars^2,3. That architecture is the article's central technical thread: it is also what let Epirus, a company founded only in 2018, beat six competing systems — reportedly including a THOR-derived entrant — in a 2023 U.S. Army fly-off and become the sole system moving toward an actual program of record^4,5.

Leonidas has since been deployed, in prototype form, with U.S. Army units in the United States' CENTCOM area of responsibility and in the Indo-Pacific, and Epirus has staged a series of increasingly large public swarm-defeat demonstrations, including a 49-drone simultaneous kill in a single microwave pulse in August 2025 and, in December 2025, the first publicly reported defeat of a fiber-optic-guided first-person-view drone by any electronic-warfare-type counter-UAS system^6,7,8.

Leonidas is built from dozens of individual Line Replaceable Amplifier Modules (LRAMs), each centered on a gallium-nitride semiconductor chip, arranged into a phased-array antenna panel roughly the size and thickness of a garage door when mounted on its towed trailer^3,9. GaN can sustain higher voltages and higher temperatures than the silicon or vacuum-tube technology it replaces, which is what lets Epirus pack comparable radiated power into a system without the coolant loops, warm-up cycle, and scheduled tube-replacement maintenance that vacuum-tube HPM sources such as THOR's require^2,9. Because the array is digitally beamformed, the same hardware can either concentrate its energy into a narrow, high-intensity beam against a single hardened target, or spread it to blanket roughly a 60-degree arc simultaneously against a full swarm, switching between the two modes at software speed rather than by physically re-aiming a dish or gimbal⁹.

Public reporting places current Leonidas variants in the kilowatt-class power range, with Epirus and Army officials describing later generations as targeting "tens of kilowatts" for greater range and lethality; neither the company nor the Army has published a specific peak-power or maximum-engagement-range figure for any generation, and this article leaves those fields blank rather than estimate them⁹. What has been disclosed is relative performance between generations: the Generation II system delivered in 2025 was reported to increase engagement range by roughly 2.5 times over Generation I in the same size envelope, raise output power by about 30%, and add an 800-pound lithium-polymer battery pack giving roughly 30 minutes of fully independent, generator-free operation, along with a "cooperative fires" mode letting two units coordinate against a shared target set^4,10. CEO Andy Lowery has cited a typical single-drone engagement time on the order of four seconds, though Epirus has not published a formal reaction-time specification¹⁰.

The base system rides on a towed, military-grade trailer roughly analogous in footprint to THOR's shipping-container form factor, but Epirus has also fielded the technology in three other configurations. A Stryker-mounted turret variant, developed with General Dynamics Land Systems, integrates the amplifier array onto the Army's wheeled armored vehicle for a mobile short-range air-defense role rather than a fixed-site one^3,9. The Leonidas Pod is a much smaller, UAV- or vehicle-portable version intended for point defense of a single position or convoy¹¹. The Leonidas Expeditionary, developed under the Navy-funded Expeditionary Directed Energy Counter-Swarm (ExDECS) program for the Marine Corps, cuts the amplifier count to roughly a third of a full IFPC-HPM system and mounts on a Joint Light Tactical Vehicle trailer, trading some power for the mobility Marine Expeditionary Advanced Base Operations require^6,12. A maritime derivative, unofficially referred to as Leonidas H2O, was demonstrated disabling small-boat outboard motors — including vessels of the type used by Houthi forces in the Red Sea — in testing during 2024 and 2025^9,13.

Cost figures are similarly approximate. Working back from the $66.1 million January 2023 contract for four Generation I prototypes yields roughly $16.5 million per unit, and reporting on the follow-on Generation II order has separately put a per-system price somewhere between $10 million and $20 million; Epirus has said it can build 20 to 30 systems a year at scale, a rate aimed at supporting an eventual Army program of record rather than a one-off prototype buy^4,9.

Epirus was founded in July 2018 by Nathan Mintz, electrical engineer Dr. Bo Marr, Max Mednik, Palantir co-founder Joe Lonsdale, Grant Verstandig, and John Tenet, incubated through venture firm 8VC's "Build" program that assembles founding teams around a specific defense technology gap rather than starting from an existing product idea^14,15. According to company accounts, Mintz's interest in counter-drone technology followed a 2018 drone incursion that shut down Gatwick Airport in the UK, after which he found existing options split between simple radio jammers and multi-million-dollar Defense Department prototypes; he and Marr began testing HPM concepts using consumer drones and bench power supplies before formalizing the company¹⁴. Epirus unveiled the first Leonidas hardware in 2020 and raised financing in stages behind it: a $17.4 million Series A in November 2019, a $70 million Series B in December 2020, and a $200 million Series C in February 2022 led by T. Rowe Price, followed by a further $250 million raise in March 2025 to prepare for volume production, bringing total funding to well over $500 million since founding^14,15,16. Much of the underlying engineering talent, including current CEO Andy Lowery and chief technology officer Matt Markel, came from Raytheon's Next Generation Jammer program, giving the startup engineers with deep prior experience building military electronic-warfare hardware despite Epirus itself being a new entrant as a company¹⁶.

Leadership turned over repeatedly as the company scaled: Mintz stepped down as CEO in 2020 in favor of Leigh Madden, a former Microsoft national-security executive and Navy SEAL; Kenneth Bedingfield, a former Northrop Grumman CFO, held the role through 2023; and Andy Lowery, who had joined Epirus in 2021 as chief product officer, was named CEO in December 2023^4,15.

The Army's interest in an HPM counter-swarm weapon predates Leonidas's selection. The service ran an Indirect Fire Protection Capability-High-Power Microwave (IFPC-HPM) competitive evaluation intended to find a fieldable system for base air defense against small Group 1 and 2 drone swarms, testing Leonidas against six competing systems, reportedly including hardware derived from the Air Force's THOR demonstrator^4,5. On 23 January 2023, the Army's Rapid Capabilities and Critical Technologies Office (RCCTO) awarded Epirus a $66.1 million Other Transaction Authority contract for four Leonidas prototypes, after the Army said Leonidas had "outperformed" the field^4,5. Epirus delivered the first unit on 1 November 2023 and completed delivery of all four by roughly March–May 2024, alongside new-equipment training and engineering developmental testing with Army crews^4,17.

Rather than wait in a lab, the Army pushed the Gen I prototypes into operational settings: reporting through 2025 describes a small number of Leonidas units deployed with Army units in the CENTCOM area of responsibility and, separately, exercised in the Indo-Pacific, including a live-fire test in the Philippines in May 2025, explicitly to generate real-world performance data rather than only range-test results⁹. In parallel, the Marine Corps and Navy pursued their own path: the Office of Naval Research, Marine Corps Warfighting Lab, and Joint Counter-small Unmanned Aircraft Systems Office funded the $5.5 million Leonidas Expeditionary / ExDECS effort in September 2024, targeting prototype delivery to the Marine Corps Warfighting Lab by the end of that year for expeditionary advanced-base defense^6,12.

Epirus staged its most prominent public demonstration on 26 August 2025 at Camp Atterbury, Indiana, before an invitation-only audience that included U.S. government representatives and delegations from nine allied countries. Across five scripted scenarios — including audience-selected targeting and a software-defined safe zone protecting a friendly drone — Leonidas defeated all 61 drones flown, culminating in a single microwave pulse that disabled a 49-drone swarm simultaneously^6,18. CEO Andy Lowery called the event "a watershed moment for Epirus" and described Leonidas as "the only mission-capable, counter-swarm solution for the one-to-many fight"^6,19.

The Army committed further funding to a next-generation version soon after. In June 2025, RCCTO awarded Epirus a $43,551,060 contract for two (later reported as three) Generation II IFPC-HPM systems, incorporating roughly 75–80% redesigned parts, a 30% power increase, a claimed 2.5-times range increase in the same size envelope, and a battery pack enabling independent, generator-free operation^4,10. The Army scheduled Gen II evaluation at Naval Air Weapons Station China Lake, California for October 2025 to test cooperative-fire engagement and engineering metrics that Lowery described as "a defining moment" for a potential move to full acquisition⁴. By mid-2025, other services and at least one ally had begun their own evaluations: the Navy planned a containerized, ship-based demonstration for August 2025, the Marine Corps was assessing a small airborne variant for individual-drone engagement, and Japan scheduled a government demonstration the same month with potential procurement contingent on results²⁰.

In December 2025, Epirus announced that a Leonidas VehicleKit (VK) system had, during a live-fire test at a U.S. government facility, disabled a fiber-optic-guided FPV drone — a threat category that cannot be jammed by conventional RF electronic warfare because it has no wireless link to disrupt, and one that has proven increasingly difficult to counter in the Ukraine war. Epirus described it as the first known instance of an electronic-warfare-type counter-UAS system defeating a fiber-optic-controlled drone⁷.

Leonidas has not, as of the most recent public reporting, been confirmed to have engaged a hostile drone in active combat. Its documented history consists of range trials, escalating public swarm demonstrations, and — distinct from THOR's purely domestic test record — genuine forward operational deployment: a small number of Gen I prototypes have been positioned with Army units in the CENTCOM area of responsibility, where U.S. and partner forces have faced persistent small-drone incursions against bases, and in the Indo-Pacific, including live-fire testing in the Philippines in May 2025⁹. No source reviewed names a specific incident in which a Leonidas unit fired on an actual hostile drone rather than a scheduled test or exercise target; the operational deployments are described as real-world assessments meant to validate the system under field conditions rather than confirmed combat engagements.

The United States, and specifically the U.S. Army, is Leonidas's only confirmed operator, holding all four delivered Generation I prototypes plus Generation II units under evaluation, following the January 2023 IFPC-HPM contract^4,5. The U.S. Marine Corps received an early Leonidas Expeditionary prototype in 2025 under the Navy-sponsored ExDECS program, and the U.S. Navy has separately tested a containerized maritime variant, though neither constitutes a service-wide fielding decision^6,20. No formal export sale has been announced. Japan conducted a government evaluation of the system in mid-2025 with procurement contingent on results, making it the most advanced known prospective foreign customer, but not yet a confirmed operator²⁰.

Leonidas's closest technological peer, by physical mechanism, is the U.S. Air Force's THOR, and the two systems make an unusually direct case study in how two organizations solved the same HPM engineering problem differently. Both generate a directed high-power microwave field intended to disable, rather than physically destroy, a drone's onboard electronics, and both were built specifically to answer the same threat: cheap FPV-style drones arriving in numbers too large for one-at-a-time interceptors to handle^1,2. Where they diverge is generation of hardware and institutional path. THOR is a government-owned AFRL demonstrator built around a vacuum-tube microwave source and a mechanically slewed gimbal antenna, developed in-house with support from BAE Systems, Verus Research, and Leidos, and it has never been assigned a program of record¹. Leonidas is a privately developed, venture-funded product built around solid-state GaN amplifiers and a digitally beamformed array that needs no warm-up or tube-replacement cycle, and it is the system the Army actually selected — over a THOR-derived competitor, among six systems evaluated — for its IFPC-HPM program in January 2023^4,5. That fly-off result is the clearest public evidence that the Army judged the solid-state approach more mature for near-term fielding, and Leonidas's subsequent Gen II contract, CENTCOM/Indo-Pacific deployments, and swarm-test results have widened the gap between a company-built product on a funded path to production and a laboratory demonstrator with no confirmed acquisition future^9,10.

Against Anduril's Anvil, the comparison shifts from shared physics to opposite ways of handling a drone swarm. Anvil is a small, expendable kinetic interceptor drone that rams a single hostile UAS to destroy it — effective, cheap per unit, and combat-proven in Ukraine, but fundamentally a one-for-one exchange that scales only as fast as interceptors can be built, launched, and guided²¹. Leonidas instead treats the entire swarm as one target: a single microwave pulse can disable dozens of drones in the time it takes an interceptor like Anvil to engage one. The trade-off is upfront cost and technical maturity — Leonidas hardware runs into eight figures per unit and remains pre-program-of-record, while autonomous interceptors like Anvil are already a fielded, comparatively low-cost, per-round expense. In practice the two are more likely to be complementary layers of a base-defense architecture than direct substitutes: a wide-area HPM system such as Leonidas to blunt a mass raid, backed by precision kinetic interceptors to mop up whatever the microwave beam does not reach or fails to fully disable⁹.

MASS Assessment

Technology (90) rates Leonidas above THOR's own strong score (85) in this archive's scoring, reflecting the generational jump from vacuum-tube to solid-state GaN emitters: a digitally beamformed, software-defined array needs no warm-up cycle or tube replacement, and the Army's own January 2023 fly-off selection of Leonidas over a THOR-derived competitor is the clearest independent evidence backing that higher rating.

Coverage (80), likewise well ahead of THOR's 30, is the more operationally consequential gap: Leonidas's growing family of mounts — towed trailer, Stryker turret, backpack-portable Pod, and JLTV-towed Expeditionary kit — lets the same core emitter technology be positioned across a much wider range of sites and formations than THOR's single container-mounted demonstrator, which has never left prototype status. That flexibility, more than raw beam power, is what has kept Leonidas moving toward an actual program of record while THOR remains a laboratory proof of concept.

Is Leonidas in service with the U.S. military? Not as a formal program of record. Four Generation I prototypes were delivered to the Army by 2024 and have since been deployed operationally — including to the CENTCOM area of responsibility and the Indo-Pacific — for real-world assessment, and Generation II units were under Army evaluation as of late 2025, but no service has announced a production program of record or a confirmed unit quantity beyond the prototypes built so far^4,9.

How is Leonidas different from THOR, the Air Force's microwave weapon? Both are high-power microwave counter-drone weapons, but THOR uses an older vacuum-tube microwave source on a mechanically steered gimbal, while Leonidas uses solid-state gallium-nitride semiconductor amplifiers in a digitally beamformed array, avoiding the warm-up time, cooldown cycle, and tube maintenance that vacuum-tube HPM sources require. The Army picked Leonidas over a THOR-derived rival in a January 2023 fly-off for its IFPC-HPM program^1,2,4.

How many drones can Leonidas disable at once? In its largest public demonstration, on 26 August 2025 at Camp Atterbury, Indiana, Leonidas defeated 61 of 61 drones flown across five test scenarios, including a single pulse that disabled 49 drones simultaneously^6,18.

Can Leonidas stop drones that can't be jammed, like fiber-optic-guided FPVs? Epirus reported in December 2025 that a Leonidas VehicleKit system defeated a fiber-optic-guided FPV drone in a live-fire test, describing it as the first known instance of an EW-type counter-UAS system doing so. Because Leonidas induces electrical faults directly through exposed wiring and components rather than jamming a radio link, it is not defeated by removing or hardening a drone's RF control link the way jammers are⁷.

What does a Leonidas system cost? Public figures are approximate. Working back from the $66.1 million January 2023 contract for four Gen I units implies roughly $16.5 million per system, and reporting on the Generation II order separately cited a per-unit price in the $10–20 million range; Epirus has not published an official unit price^4,9.