The drones began crashing on the Ukrainian front without much explanation.
For months, the aircraft supplied by Quantum Systems, a German technology company, had operated smoothly for the Ukrainian military, flying through the air to detect enemy tanks and troops in the country’s war against Russia. Then, late last year, the machines suddenly began falling from the sky as they returned from missions.
“It was this puzzle,” said Sven Kruck, a Quantum executive who received a stern letter from Ukraine’s defense ministry demanding a solution.
Quantum engineers soon realized the problem: the Russians were jamming the wireless signals connecting the drones to the satellites they used for navigation, causing the machines to become disoriented and crash to Earth. To adapt this, Quantum developed artificial intelligence-based software that acted as a sort of secondary pilot and added a manual option so that the drones could be landed using an Xbox controller. The company also built a service center to monitor Russia’s electronic attacks.
“All we could do was get information from the operators, figure out what didn’t work, test it and try again,” Mr. Kruck said.
In Ukraine, a battle is raging in the invisible range of electromagnetic waves. Radio signals are used to overwhelm communication links with drones and troops, to locate targets and to outwit guided weapons. The tactic, known as electronic warfare, has become a cat-and-mouse game between Russia and Ukraine, quietly causing dynamic swings in the 21-month-old conflict and forcing engineers to adapt.
“Electronic warfare has influenced the fighting in Ukraine as much as the weather and the terrain,” said Bryan Clark, a senior fellow at the Hudson Institute, a think tank in Washington, adding that every operation in the conflict now affects the enemy’s movements must be taken into account in the electromagnetic spectrum.
Electronic warfare has been a part of war for more than 100 years. During World War II, the British mimicked German radio signals to deceive targeting systems used by bombers, which Winston Churchill popularized as the “Battle of the Rays.” During the Cold War, the Soviet Union invested heavily in electronic weapons to gain an asymmetric advantage over the United States’ missiles and aircraft.
In recent decades, the use of electronic attack and defense systems has been more one-sided. During the Iraq War in the 2000s, the United States used so-called jammers to generate so much radio noise that improvised explosive devices could not communicate with their remote detonators. More recently, Israel has mixed GPS signals in its airspace with electronic warfare systems to confuse possible attacks by drones or missiles.
The war in Ukraine is the first recent conflict between two large and relatively advanced militaries to make extensive use of electronic warfare capabilities and advance techniques in real time. Once the purview of trained experts, technologies have expanded to frontline infantry forces. Ukrainian drone pilots said they had continually refined their methods to counter the unseen attacks. Someday a new radio frequency could work, some said. Next, another antenna.
The tactics have become so critical that electronic warfare was given its own section in a recent essay by Gen. Valery Zaluzhny, Ukraine’s top military commander. “The widespread use of information technology in military affairs” is the key to breaking the stalemate in the conflict with Russia, he wrote.
The techniques have turned the war into a proxy laboratory that the United States, Europe and China have been watching closely to figure out what could influence a future conflict, experts said.
Gen. Charles Q. Brown Jr., chairman of the Joint Chiefs of Staff, raised the issue of electronic warfare in prepared remarks for a congressional hearing this year. NATO countries have expanded their programs to buy and develop electronic weapons, said Thomas Withington, an electronic warfare expert at the Royal United Services Institute, a British security think tank.
“The war in Ukraine was the performance-enhancing drug for NATO’s electromagnetic thinking,” he said. “It is what concentrates the mind.”
Antennas and jammers
When Russian tanks rolled toward Kiev in February 2022, the Russian military first confirmed its reputation as one of the world’s best in electronic warfare. It used powerful jammers and decoy missiles to swamp Ukrainian air defenses, leaving Ukraine dependent on aircraft to fend off Russian aircraft.
At first glance, the electronic weapons do not appear dangerous. These are typically satellite dishes or antennas that can be mounted on trucks or placed in fields or buildings. But then they emit electromagnetic waves to track, trick and jam sensors and communications links that control precision weapons and enable radio communications. Almost every communications technology relies on electromagnetic signals, be it soldiers using radios, drones connecting to pilots, or missiles connecting to satellites.
A simple but effective tool is a jammer, which disrupts communications by emitting strong signals on the same frequencies used by walkie-talkies or drones, causing interference so strong that sending a signal is impossible. Jamming is like playing heavy metal in the middle of a college lecture.
Another key weapon sends a signal pretending to be something it is not, such as a satellite link. The fake signal, known as spoofing, can convince a drone or missile that it is miles off course by feeding it false coordinates. In other cases, spoofers mimic the signals of missiles or aircraft to trick air defense systems into detecting attacks that are not occurring.
Other tools pay attention to beams of radiation and try to locate their origin. These devices are often used to find and attack drone pilots.
After initial success using these tools, the Russian military stumbled, analysts said. But as the war has progressed, Russia has innovated by producing smaller, mobile electronic weapons, such as anti-drone cannons and tiny jammers that create a radio wave bubble around trenches.
“The Russians responded more quickly than we would have expected based on their behavior on the ground,” said James A. Lewis, a former U.S. official who writes about technology and security for the Center for Strategic and International Studies in Washington. “This should be a concern for NATO.”
The Kremlin did not respond to a request for comment.
Soviet vs. start-up
To combat Russia’s centuries-old Soviet know-how in electronic attack and defense, Ukraine has turned to a Silicon Valley-related start-up approach. The idea is to help the country’s engineers quickly produce electronic warfare products, test them and then send them to the battlefield.
This summer, the Ukrainian government hosted a hackathon for companies to work on ways to block Iran’s Shahed drones, which are long-range unmanned aircraft used to attack cities deep in the country, said Mykhailo Fedorov, Ukraine’s digital minister .
At test sites outside Kiev, drone manufacturers are testing their vehicles with electronic attack weapons. In a field in central Ukraine in August, Yurii Momot, 53, a former Soviet special forces commander and founder of the electronic warfare company Piranha, showed off a new anti-drone weapon built for the conflict.
The weapons performed inconsistently in the war, but Mr. Momot’s version worked. He pointed it at a DJI Mavic, a regular cheap reconnaissance drone, and pulled the trigger. The drone hovered motionless. His navigation system had been overwhelmed by a barrage of radio signals from the gun.
“The whole system is more structured in Russia,” Mr. Momot said of the Russian electronic warfare program, which he knows from his time in the Soviet army. “We’re catching up, but it’s going to take a while.”
Other Ukrainian companies like Kvertus and Himera are building tiny jammers or $100 walkie-talkies that can withstand Russian jammers.
At Infozahyst, one of Ukraine’s largest electronic warfare contractors, engineers recently worked on a project to track and identify Russian air defense systems. Iaroslav Kalinin, the company’s chief executive, said Russia’s anti-aircraft radar would not be as easy to replace as tanks. But if enough of them were eliminated, it could be a turning point in the war.
“Once we control the skies, Russia will fail badly,” he said.
A call to action
This summer, Oleksandr Berezhny, a Quantum executive, traveled with one of Ukraine’s top drone pilots to share their knowledge of electronic warfare with NATO. At a large round table at a base in Germany, they explained the problems they faced to an enthusiastic audience of commanders.
“We told them that probably 90 percent of the American and European systems coming to Ukraine were not prepared for the challenge of electronic warfare,” Mr. Berezhny said. “There was an absolute understanding that something had to change.”
While Ukraine offers a glimpse of how future electronic battles might be fought, potential combatants in these fights have taken note. The United States and Europe have watched closely how such weapons have fared against Russian systems, and some fear they are not responding quickly enough. Chinese experts have also documented in detail which Russian electronic attacks against NATO systems were most effective and where Russia failed.
In a November 2022 report, a Chinese defense think tank detailed how a Russian electronic attack had tricked NATO’s detection equipment and caused Ukraine to reveal the location of its own electronic defense assets.
“The Russian army’s anti-drone capabilities are superior to those of the US military,” the report said.
As Ukraine develops its anti-jamming techniques, some of those tactics are trickling down to the United States and its allies, said Mr. Clark of the Hudson Institute.
“Now you see countries including the United States deploying these smaller systems, just as you see people in Ukraine cobbling them together,” he said.
For many on the Ukrainian front, improvements cannot come fast enough.
“Even if you make your drone invisible, your controller and antenna give out a signal,” said a Ukrainian drone pilot who gave only his first name, Vladislav. The Russians could see a window of about 200 square meters where a drone pilot could be, he added, noting that artillery was once “about 15 to 20 meters” away from being hit.
“It is not possible to hide completely,” he said.
Olha Kotiuzhanska reported from Kiev, Dnipro and Odessa, Ukraine. Arijeta Lajka contributed a video production from New York.