Shoulder fired aimed EMP weapons have been designed, patented and are in testing since 2019. Their primary purpose is to scramble the electronics of small lethal drones. Seems to work and is relatively inexpensive. It's a piezoelectric generator with focused antenna attached to an M4 rifle. It uses the energy of a blank cartridge.
AeroVironment's Switchblade 300 has a 20+ km range at 63 mph. 18 km with 100 mph sprint speed. Under development now are autonomous, AI operated drone killer drones. One can only wonder how fast the modern battlefield will disappear like Napoleonic tactics...
You can see the jamming happening right now in most recent drone footage. I don't think Russia was ready for the drone menace early on. But jammers/jamming is pretty common now in Ukraine. If you see any drone footage where a drone is diving in on a target and they go static as they approach that's the jamming happening.
For now, they have limitations. The race is on for countermeasures for jamming and also jam proof signals.