They can, and do. They’re just expensive and complex to make, and ensuring one works takes a lot of trial and error, which – as I said – is expensive.
Ukraine has only recently (about this spring) started to use self-aiming drones that lock on a target, disable guidance input, and jamming at this point doesn’t matter, since it auto-flies to target. This makes it more of a loitering munition. And this still works only if drone can get close enough to get a lock-on, without being disabled.
But they’re still using those to target military targets, not jammers. Smaller jammers are tricky, you can put put them into cover or forest, hide into tree branches or whatever, and drones can’t quite reach them. Only big EW vehicles with radars are more easily targetable, but you can target them as well with artillery then – drones are used for precision strikes and fast-moving targets.
Also, for drone to “home in” to a signal, it needs a clunky detector for that signal receiver. Which leaves less available weight for explosives. Which makes it a crappy drone.
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