Microwaves versus drones. How engineers are mastering electromagnetic weapons
The world is perfecting prototypes of microwave weapons to use them in combat. Will such weapons be useful in the Russo-Ukrainian war?
The history of the microwave oven is quite unusual: it began with the production of radar systems during the bloodiest conflict in human history, World War II.
The principle of radar is simple: the system emits electromagnetic waves that are reflected from enemy objects and returned. Thanks to an antenna and several mathematical formulas, radar stations can determine an object's location, direction of movement, and approximate size.
The power of radar was limited at the time, so American and British engineers were tasked with inventing a device capable of generating shorter waves of much greater strength. The result was the invention of the magnetron.
It transformed radar surveillance and made it more effective. After World War II, during tests, one of the engineers noticed that the waves melted a chocolate bar in his pocket. As it turned out, the waves made water molecules move and heat the food. This is how the first microwave oven was created.
Eighty years later, microwaves themselves are inspiring engineers to develop new weapons. If a microwave oven can incinerate sandwiches, can it do the same to enemy drones or even manpower, provided the electromagnetic waves are powerful enough?
Defence companies around the world are looking for an answer to this question.
How do microwave weapons work?
It is unlikely that the military would now be thinking about developing lasers or combat microwaves if it were not for the emergence of cheap kamikaze drones. Usually, air targets are shot down with expensive anti-aircraft missiles, but in a long-term war, these will not be enough, as thousands of cheap drones can be produced per month.
Up to US$200,000 can be spent on an attack drone. However, an anti-aircraft missile costs more than €1 million for the IRIS-T system and about €3 million for the Patriot air defence system.
Drones can also be used not by the military but, for example, by terrorists. A striking example is the Yemeni Houthis, who have launched cheap UAVs at civilian and military vessels in the Red Sea. Thus, the development of defence equipment is a challenge for all armies in the world.
Electronic warfare systems cannot completely block the sky from kamikaze UAVs, as modern Controlled Reception Pattern Antennas (CRPAs) can protect satellite communications on drones, and drones themselves often have autonomous guidance systems.
There are two ways to reduce the gap in the cost of attack and defence capabilities. The first is to develop alternative means of destroying air targets. A notable example is that Ukraine has begun using anti-aircraft FPV drones that cost several hundred dollars each.
The second way is to develop an air defence system that does not require ammunition. Science says it is possible. This refers to so-called directed-energy weapons (DEWs). The idea is to damage the target with electromagnetic waves. This can be a directed beam of light, i.e. a combat laser, or strong microwave radiation.
Modern combat lasers costing a few cents per shot can burn a hole in a target tens of kilometres away in a matter of seconds, disabling its electronics. However, many conditions complicate the process of mass adoption of this technology in the military.
The laser needs a powerful source of energy, a cooling system, and trained technicians to maintain it. The weather must be clear, as fog scatters the beam. Such a weapon can only target one thing at a time, and its development is quite expensive, even by the standards of Western companies.
Microwave weapons work differently. They do not burn the target from the outside and do not deform its body, but they can disable electronics. The electromagnetic energy of these systems is enough to cause a malfunction in the sensitive electronic components of the object and make it fall.
The disadvantage of this concept is that microwaves cannot reach the target as far as lasers. However, their advantage is that they suppress multiple targets in a direction set by the operator. This makes such systems a promising weapon against drone swarm attacks, where dozens of targets need to be covered simultaneously.
Lasers and microwave systems have strengths and weaknesses. The US Navy is testing both options and plans to combine them in the future to protect vessels from drones.
There are also different concepts for using microwave weapons against enemy manpower or to counter civil unrest. These are called Active Denial Systems in the United States.
The effect is as if a person were placed in a microwave oven. The system can cause burns and create significant discomfort, forcing you to run away as far as possible. It sounds creepy, but open research data published in Wired magazine has shown the relative safety of this technology.
Only a few people out of thousands of test subjects experienced significant burns, and in most cases, the pain disappeared immediately after the system was turned off.
However, it is still a mystery how harmful it will be when used on people in real life.
One theory suggests that microwave weapons were the cause of the Havana syndrome among US diplomats in Cuba. Havana syndrome refers to mysterious health problems that employees of the US embassy experienced for months for unknown reasons. The people suffered from insomnia, memory loss, balance disorders, headaches, and impaired concentration.
The idea of using a DEW sounds promising, but the technology is still raw and requires years of development. A common problem with lasers and microwave systems is their doubtful effectiveness in combat.
The SWaPC formula, which measures the size, weight, power, and cost ratio, determines the technology's readiness for mass use in the army. In the case of lasers and microwave weapons, it is worth adding another variable – power consumption.
Read more: A weapon entirely immune to jamming: How Ukraine is rolling out production of fibre-optic drones
The first microwave and laser weapons turned out to be large, heavy and expensive. They needed a powerful on-site power supply. The problems began at the stage of delivering systems to the battlefield and arranging infrastructure for them. Possible errors when working in different weather conditions for different purposes require additional research and testing.
Such research continues. For example, the US Army sees potential in DEWs and spends about US$1 billion annually on their development. Lasers are still a more popular concept, but some defenсe companies have already created the first working samples of microwave weapons. It's not just about corporations from the United States.
Which countries have microwave weapons?
No model of microwave weapons has yet gone into mass production. Promising samples are currently being tested and are likely ready for trial applications in real combat conditions.
One of the most popular prototypes is the THOR system from BAE Systems, Verus Research and Black Sage. It is housed in a 20-foot container, its size adapted for transporting by the most popular American cargo aircraft, the C-130 Hercules. THOR can be prepared for combat on the battlefield in three hours.
The main stated advantage of the THOR system is its effective combat capability against drone swarms. The US Air Force Research Laboratory conducted tests in 2023 to simulate a drone swarm attack. The system successfully repelled the attack with microwave weapon radiation. However, the details of this test remain unknown.
Conceptually similar to THOR are the Chimera and Phaser systems developed by Raytheon.
Another American prototype of a microwave weapon is the Leonidas from the company Epirus. This is a more compact and less powerful option compared to the previous ones. Its advantage is its high mobility. The developer is working with General Dynamics on systems to integrate it with the Stryker armoured personnel carrier.
China, which does not lag behind global technological trends, also has its developments in the microwave weapons segment. Three models from state-owned Chinese companies have been noticed in propaganda videos by reviewers from The Warzone magazine.
The first one is small, mounted on an armoured personnel carrier. The second and third are heavy and installed on massive trucks.
Various countries have developed microwave weapons against manpower since the 2000s. Not just the United States, but also Russia and China. However, the technology has not taken root in the armed forces and looks more like a tool to be used against protesters.
Nothing is known about microwave systems in the Ukrainian defence forces. In the long run, this technology could protect the sky from Shahed-type kamikaze drones and defence forces’ positions from FPV drones.
Although domestic engineers have made some achievements in producing electronic warfare equipment, developing microwave weapons and bringing them to combat readiness requires a lot of time and resources.
Bohdan Miroshnychenko
Translation: Myroslava Zavadska and Yuliia Kravchenko
Editing: Susan McDonald