Fighting the war in Ukraine on the electromagnetic spectrum
FOR SOLDIERS at the front, electromagnetic defences are as vital as air: invisible when present, and disastrous when not. In July Ukrainian troops in southern Donbas found this out the hard way. Abruptly, Russian drones switched frequencies, from standard 700-1,000 megahertz to 400-500 megahertz, blinding Ukraine’s electronic-warfare (ew) systems. The drones flew deep behind the lines, cutting off units and making supply routes impassable. Tens of Ukrainian military vehicles were destroyed daily in what Serhii Beskrestnov, a Ukrainian EW specialist, calls a “Russian safari”. Only when Ukraine understood what was happening, and secured new EW systems working at 500 megahertz, weeks later, were they able to stabilise the situation.
The war of waves has been pivotal to the wider conflict. A continuous and intense contest between munitions and jammers is driving rapid change, as each side scrambles to find, monitor, occupy and attack increasingly rare gaps in the spectrum where signals can get through. “What you’re seeing in Ukraine is electromagnetic manoeuvre warfare in action,” says Thomas Withington, a fellow at the RUSI think-tank. “Much as land forces are always moving to find that high ground or key crossing, so too are electronic ones.” As jammers become more numerous and more sophisticated, the quest for jam-proof drones becomes ever more urgent.
Russia began its all-out invasion with colossal advantages. It was the world’s EW superpower—if measured by the quantity, might and variety of its systems. It dominated the initial exchanges, jamming much of Ukraine’s military communication. Elon Musk’s Starlink, a secure satellite-communication network, gave a lifeline to Ukraine. Then, in 2023, came the drone revolution. Ukraine pioneered the use of first-person-view (FPV) drones to search, chase and destroy enemy targets with pinpoint accuracy. “Without the proper drone and electronic warfare support, an infantry unit will survive only a few hours on the battlefield,” says Major Dmytro Tolstoluzhsky, an officer in a specialised technology unit of Ukraine’s defence ministry. The task of EW turned to neutralising the drones, loitering munitions and glide bombs that now dominate the skies.
The new war exposed vulnerabilities in Russia’s extremely powerful but bulky EW systems, which became liabilities lying within FPV drone range. They were forced to retreat a full 10-15km away from the front line, diluting their effect. Meanwhile, Ukraine began to make progress expanding its own EW capacity, with local producers scaling up production of trench-level EW systems. Yaroslav Filimonov, the chief executive officer of Kvertus, a Ukrainian company that specialises in EW, says monthly production jumped from 100 devices at the start of 2022 to 1,000 by 2023, and is now up to 5,000. At least 200 companies now work on EW, says Mr Withington.
The basic science of a front-line jammer is not complicated: a cheap metal box with aerials generates electromagnetic noise to block piloting signals or video feeds. Both sides rely heavily on commercially available Chinese components. But beyond this is a constantly evolving, high-stakes technological arms race. Every eight to 12 weeks sees a major change in either EW or drone practice, says Major Tolstoluzhsky. Both sides switch within a wide frequency spectrum from 200 megahertz to 1,000 megahertz, and above. But the “main race” last year, says Andrey Liscovich of the Ukraine Defence Fund, a non-profit which sources non-lethal aid, was a shift in frequencies down from standard GSM bands—those used by mobile phones—to 300 megahertz, making it trickier to find off-the-shelf components.
The result of these proliferating frequencies is vehicles that resemble steampunk porcupines, bristling with half a dozen antennae to protect against different drones, each drawing significant power.
Defenders also have to know where and when to focus their attention. Using a device which spits out a lot of radio waves not only risks electronic fratricide, but also makes the user a potential target. Knowing when to turn it on, and on which frequency, depends on passive sensors which can triangulate radio emissions from the other side to work out their source. The sensors used early in the war, to spot cheaper Chinese-made drones, are no longer as useful. Some of today’s sensors are in space: Ukraine is using data from satellites built by HawkEye 360, an American firm.
More common is a spectrum analyser, a small $7,000 box, which picks out the different frequencies broadcasting at any time. That information can then direct your jamming. In theory, spectrum analysers could be strung together to create a giant electronic picket to detect emissions all along the front line. That would cost around $10,000 per kilometre of front, estimates Mr Liscovich, perhaps $10m for the entire stretch—a modest amount. The problem, as with so much else in the war, is supply chains. Only three companies in America and Germany build the devices; turnaround times are eight months.
Both sides are also experimenting with cleverer methods. Mr Filimonov describes Azimuth and Mirage, a pair of products: the first picks up signals within 25km and feeds it to the second, which uses software to generate waveforms on the right frequency. In theory, that frees up the need to carry around several different jammers. But both sides can make disruptive changes. “This is a field of science where everything can be upended in the shortest of time,” says Lieutenant Colonel Oleksandr Korobka, who heads an EW unit in Ukraine’s 54th brigade.
The top-end Russian drones, for example, have already evolved to include backup piloting systems. They may switch from standard GPS to satellite-led or inertial-navigation systems, which use gyroscopes and accelerometers to work out a drone’s real position. They may also use artificial intelligence (AI) or communication with beacons on the ground to move drones to a target or back to base. “In such a case full EW defence is practically impossible,” says Colonel Korobka.
The newest challenges are last-mile automation and fibre-optic drones. Last-mile automation avoids most tactical EW shields, which have a range of about 50m, by guiding drones to near a target, and then using AI to visually lock on and strike. Fibre-optic drones, first seen on the battlefield in the spring of 2024, unwind spools of tiny cable as they fly, making them more difficult to manoeuvre but impervious to EW interference. Fibre-optic drones often spearhead attacks, targeting and destroying EW systems first so other radio-piloted drones can follow. Both sides are in the process of ramping up the technology. Russia, the first-adopter, has a lead. Mr Filimonov says that methods such as stroboscopes—flashing lights to dazzle the drone’s cameras—are also being tested.
For now, most drones are still jammable. And Ukraine still has the edge in EW. “They’re certainly quicker than the Russians,” says Mr Withington. The war has also made them quicker than many Western competitors. Mr Filimonov visited 15 military exhibitions around the world last year. The EW technology he saw was not only pricier—American and European amplifiers are two to three times more expensive than the Chinese ones commonly found in Ukrainian kit—but also obsolete. “These technologies are somewhere in 2021,” he says, witheringly. “Everything they are producing is, for the moment, useless on the front line.” ■
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