Why Shoot Down Houthi Missiles When We Could Microwave Them?

A conceptual image showing Ratheon’s DEFEND system beaming high-power microwave energy at an … [+] airborne drone.

Raytheon

Raytheon’s high power microwave system may one day knock down drones, missiles, and more with the repeatability of your countertop oven.

The company says its ground and ship based high-power microwave (HPM) air defense system is now small enough and powerful enough to defeat airborne drone, missile and other threats at “tactically relevant” ranges.

This year and in Fiscal 2026, Raytheon will deliver prototypes of its DEFEND system to the U.S. Air Force Research Laboratory, the Naval Surface Warfare Center Dahlgren Division and the Undersecretary of Defense for Research and Engineering for field testing.

DEFEND stands for Directed Energy Front-Line Electromagnetic Neutralization and Defeat, a program which grew out previous HPM projects including the Air Force’s Counter-Electronic High-Power Microwave Extended-Range Air Base Air Defense (CHIMERA) and the containerized Tactical High-Power Operational Responder design (THOR).

The concept behind DEFEND (as well as CHIMERA and THOR) is to use microwave energy as an effector, essentially pulsing high power microwave bursts at a drone, missile or other airborne threat at tactically meaningful (classified) range to destroy its internal electronics, causing it to veer off course and crash before reaching its target.

“Every new threat that we see, a drone, a missile or an aircraft – they’re all reliant on increasingly complex electronics,” Raytheon’s director of next generation technologies for the DEFEND Program, Paul Head, explains. “If we can disrupt those electronics, we can prevent that threat from doing its job.”

A Raytheon graphic depicting the battlefield of 2025 and area defense with integrated directed … [+] energy systems.

Raytheon

The benefits of preventing threats were underlined again on Monday when a Houthi-fired anti-ship ballistic missile struck a U.S. owned and operated container ship in the Red Sea.

But well before the yesterday’s attack, demand for the development of directed energy systems, whether HPM, laser or other formats, had skyrocketed.

This has been driven by both the kinetic effectiveness of drone warfare as seen in Ukraine (and in a 2019 attack on Saudi Arabia’s oil infrastructure) and more recently Houthi drone and missile barrages in the Red Sea which have demonstrated the asymmetric cost (i.e. relatively cheap) advantage of using modestly-priced UAVs and cruise missiles to overwhelm air defenses and exhaust stocks of highly expensive anti-air missile interceptors.

But like lasers, HPM systems have theoretically unlimited magazines so long as a high-power source is available for them to tap. Super dense bursts of radio-frequency (RF) microwave power are also magnitudes cheaper on a per-shot basis than firing guided missile interceptors or even guided cannon or machine gun fire.

Raytheon’s DEFEND system consists of a power generator, a transmitter, an antenna that allows for compression of electromagnetic energy into short peak power pulses and a guidance system to direct the energy at incoming targets.

According to Head it is still fairly large, “on the order of a 20-to-40 foot CONEX box [basically a maritime shipping container] with an antenna on top”. That makes it nearly identical to a previous experimental Raytheon counter-drone HPM system called “Phaser” from which it is likely derived.

Raytheon’s Phaser counter-UAS system as seen in 2019.

Raytheon

A system so-sized could fit onto a ship or be towed near the front lines on land by tactical wheeled vehicle. Head confirms that DEFEND is intended as a front-line air defense system and that Raytheon and others are working on decreasing its size, weight and power (SWaP) requirements.

Microwaves are longer than infrared radiation but shorter than radio waves, generally between one gigahertz (GHz) and three gigahertz. They can encompass highly-dense potential energy. They’re also fast. Traveling at the speed of light, they are 40,000 times faster than the swiftest ballistic missile.

That means they can rapidly reach out and touch even hypersonic airborne targets. Microwaves also tend to match or be near the operating frequencies of most electronic systems. The HPM systems in development by the U.S., China, and Russia are thought to be able to generate high power bursts in a microwave frequency range of roughly 1 to 35 GHz, cutting across a broad range of electronics from military to consumer systems.

There are numerous pathways and entry points through which microwave emissions can penetrate electronic systems – through a target’s own antenna, dome, or other sensors. They can also travel through cracks, seams, trailing wires, metal conduits, or seals of the target – a pathway called the “back door.”

Their effects depend on the amount of power generated by an HPM system, the distance between the weapon and target, the characteristics of the microwave emission (frequency, burst rate, pulse duration, etc.), and the vulnerability of the enemy target. That gives defensive systems like DEFEND the ability to merely disrupt airborne targets at longer ranges or fry them internally at medium ranges.

Not surprisingly, Paul Head declined to comment on any power, frequency or range details of DEFEND. Microwave signals are line-of-sight. Their range is limited as the earth curves away from the transmission source. However, it’s worth noting that terrestrial microwave communication links can travel out to about 40 miles.

Highly energized HPM signals might go substantially farther and given that DEFEND’s targets are airborne, the line-of-sight equation changes. HPM beams or bursts do need to be directed to their targets. For DEFEND and its Phaser predecessor, this is likely done via radars or electro-optical and infrared cameras to help cue the system.

Among the advantages of HPM is that it is less affected by atmospheric interference than lasers which can be thrown off target by rain, clouds, or dust. The breadth of the energy pulse is generally wider than a laser, making targeting a bit less exacting.

All of that, along with cost, adds up to potential. The Air Force, Navy and Raytheon see HPM as part of a layered air defense, complimentary to existing missile and artillery interceptors and in the future with laser systems. A system like DEFEND could help “thin the [target] heard” a company spokesperson stressed.

“If you have 20 incoming threats, and even if your HPM can only address half of those, that’s 10 fewer threats warfighters need to deal with.”

The lower cost-per-shot business case of directed energy weapons is further bolstered by blending them within existing ship and land-borne air defenses Head adds.

“One of the things that we at Raytheon are spending some of our own money on is looking at how it integrates with the systems we have today … It’s great for us to be able to hand our warfighters a new tool but if they don’t understand how to use it effectively, it won’t be that useful.”

Air Force Research Laboratory researchers making final touches on the CHIMERA equipment prior to … [+] conducting system tests.

Air Force Research Laboratory

The development of DEFEND and other directed-energy systems is reaching tactical practicability. There is the possibility we may see them begin tactical operations on ships or the front lines in a couple years. Knocking down Houthi missiles or drones or thwarting Russian drones in eastern Ukraine with inexpensive HPM anti-air systems has obvious appeal.

But HPM also brings with it a conundrum. It can be turned on ground targets as well. On the battlefield, ground-based HPM systems could stop enemy robotic or autonomous weapons in their tracks.

A U.S. program called HiJENKS (High-Powered Joint Electromagnetic Non-Kinetic Strike Weapon) aims to destroy or disrupt ground targets from airborne platforms (fighter, drone or command-control aircraft) across wide-swaths of territory. China and Russia are looking at similar HPM and directed energy weapons.

These would put mobility at risk – not only military tanks, armored vehicles, robots or self-propelled artillery whose electronics they would seek to fry – but also civilian systems well behind the lines from communications to utilities. They could also halt civilian transportation (cars, trucks, light rail). This risk is now heightened by the push to electrify these systems, making EVs – consumer or military – especially juicy targets.

Raytheon’s DEFEND program director says he is aware of the potential to turn directed energy against America’s military and civilian infrastructure but that the company thinks the best defense is a good offense.

“Our focus has been to make sure we are equipped to deal with the threats we’re seeing which are more and more reliant on their electronics,” Paul Head affirms. “I think that if we’re the leaders and develop these [HPM] weapons ahead of our adversaries, then we’re better prepared to deal with [directed energy threats] and force that conundrum back on our adversaries.”

If it works, DEFEND would surely be handy in microwaving-away the Houthi threat to shipping and the world economy.

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