Leonidas, a new system developed by Epirus Inc, has been demonstrated on a Stryker vehicle. Able to keep up with armored formations, or park and sweep the skies over a city, Leonidas can cook the electronics of incoming missiles and drones, causing them to malfunction and plummet to earth.
Say hello to the future of air defence and area denial. No boom. No zoom. No pew-pew-pew. Just silent high power microwave (HPM) energy frying the microelectronic circuits that make the drone, missile, or aircraft fly. Unshielded, the wires and circuits of the aerial weapon become apertures for the blast of microwave energy. The power supply of the targeted weapon then overloads the system. When the resulting voltage exceeds the tolerances of any conductor, one might only hear a pop, like a kernel of corn in your microwave. Silent but destructive.
Nuclear EMP (electromagnetic pulse) is a Cold War legacy fear. Discovered during the 1962 Hardtack Teak experiments, in which thermonuclear bombs were detonated in space over the Pacific, producing oscillations in the planetary magnetosphere, it is a brute force method of potentially knocking out a society that is dependent on electronics.
Leonidas has the same effect on electronics, but without the messy radioactive mushroom clouds of World War III. While the technology used to build Leonidas is as old as the first radio sets, Epirus uses innovative new materials to shrink the system down to a size that can be deployed and mobilized on existing platforms.
Using a combination of active phased array (the big rectangular paddle antenna) with solid-state radio frequency (RF) amplifiers made of gallium nitride instead of vacuum tubes, Leonidas uses the waveform itself as weapon, pulsing microwave energy across a narrow beam or a whole section of sky, not on one frequency but across a whole section of the electromagnetic spectrum.
This is the key advantage of HPM weapons over high-energy lasers (HELs), which focus energy on a specific point to inflict damage. “We create shields of energy rather than shooting a bullet of energy,” Andrew Lowery, chief product officer at Epirus, explains to the Journal of Electromagnetic Dominance.
Shields up! Epirus is only one of many HPM system developers profiled in the article. Expect more new EMP weaponry profiles soon. This is a military revolution in progress.
Here is a company promotional video of the first version of the Leonidas system. Published over a year ago, it shows the Epirus product taking down a whole swarm of drones at once. Russian use of Iranian Shahid-136 “kamikaze drones” in waves, aiming to saturate Ukrainian defenses and thereby score critical hits to electricity infrastructure and other targets, portends the future development of such swarms.
In this second video, the system is demonstrated taking down a variety of drones, including groups of different drones operating in the same area. Future drone warfare is likely to feature mixed platforms working together: loitering munitions looking for targets, quadcopters directing artillery fire, and so on, all at once. Some may be purpose-built, say for electronic warfare, while others are designed to all work the same way, perhaps hundreds or thousands at a time.
Electromagnetic spectrum operations (EMSO) is a force multiplier. That is, the “art” of EW is in the creation of windows of opportunity for action by other arms, and denying the same ability to an enemy. To accomplish this, EW units often use dismountable systems. Drones have become the new dismount.
The Phase 1 system in these videos was improved and ruggedized into the Phase 3 version, as seen on the Stryker last April. Being a software-defined system, it operates without the need for a specialized interface. A drone copter version, the Leonidas Pod, can add overhead coverage — or attack the electronics of an enemy, for example by targeting the air defense systems in advance of a drone swarm attack, or just before a missile salvo. The US Air Force already has a missile system, HiJENKS, to do the same thing. EMSO soldiers will sweep friendly skies, or clear lanes through enemy skies, with a combination of wheeled and flying and missile platforms.
Ukraine would be a good proving ground for these technologies. They could be a real overmatch against Russian capabilities, a genuine “game changer.” Whereas Epirus is just one company now turning out products like these in the west, responsive development of reliable HPM weapons could be a huge additional procurement challenge for Moscow. If information about any HPM systems arriving in Ukraine comes to my desktop, be sure I will write about it.

The advent of a flying microwave shield wall to hold the line against a future locust-swarm of drones also suggests the shape of future naval conflicts. Consider the Taiwan Strait and the South China Sea, a newly-hot potential theater of conflict. China seems to think they can overwhelm Taiwanese defenses and hold off American intervention with a superior fleet size using lots of missiles and drones.
As I have explained before, China is testing out new ways to dominate the EM spectrum in the Taiwan Strait, potentially altering the art of naval construction by centering the drone swarm in ship design. Taiwan will defend itself with a drone swarm in the air as well as on the sea — and under it — meeting the Chinese threat by remote control. Both sides will use drones against drones. HPM could be the killer app (heh) in that environment.
Watching Leonidas, I am reminded that recent US Navy procurement failures may be a good thing, since the fleet did not add them in great numbers. Answering the potential novel threat of a Chinese drone carrier fleet does not require an innovative new form of deep water, “blue navy” warship.
Instead, the decisions to focus on upgradeable systems, such as the Phalanx close-in missile defense system, and leave room in new hulls for added power capacity, will allow directed energy weapons to replace some functions of older naval warfare technologies.
Known to a prior generation as “particle beams,” HELs are a good example of a technology that has been around for a long time, but which has lacked a use case that required it instead of, say, a missile or a bomb. As they are line-of-sight weapons, lasers cannot be used for indirect fire missions, so they cannot replace missiles or even gunnery. Instead, they will have to compete with HPMs, or complement them, in order to be viable.
Leonidas is probably not seaworthy yet. However, it would only take a little engineering to mount, say, two units on a frigate, or four on a cruiser, and provide 360-degree “shielding” against aerial drone threats, missiles, and aircraft. Effective range is already 10 km, about double what Phase 1 produced. At that rate, in a decade the Navy could sail with HPMs that rival the range of anti-ship missiles, and then American surface ships might not be obsolete, after all.
So why would anyone also want a laser if they can have HPMs? The answer is physical shielding. Faraday’s law and insulated wiring. US and NATO veterans of a certain age will remember the cumbersome cables and grounding stakes. These things used to be embedded in procurement processes, and now that engineering will make a comeback.
Concern about potential use of EMP detonations to destroy a defender’s ability to resist an attack led both sides of the Cold War to develop EMP-hardened aircraft, tanks, trucks, and radios. We will see it all again as features on new weapon systems. Iran will develop a new Shahid drone model with improved EMP resistance. China will develop missiles and drones that resist some voltage level, so then weaponmakers will advertise EMP weapon upgrades to double their power output. And so on.
If this military revolution unfolds like others before it, there will be weapons that Leonidas cannot stop, and then someone will want a laser to shoot down those HPM-hardened drones and missiles and jets. Likewise, Phalanx is not going away — just in case something gets past both the laser and the microwave shield, so that a physical spray of flying lead projectiles must knock it down.
Ignore the obituaries for every legacy weapon system under the sun. Get ready for the directed energy revolution to make everything old new again.