No matter how expensive the "gun" is, you cannot really direct an EMP wave and restrict it like a traditional borescope weapon. All it will take is for someone firing it across an ILS transmitter array at a drone on the other side, and the airport loses their Cat II landing capability just as the airport gets socked in.
That's also ignoring the fact that if the signal to a drone is lost, it's more than likely to fall out of the sky like a ton of bricks.
Consumer drones typically have well-defined and behaved signal loss behavior, which (for DJI ones at least) is even fairly configurable. Though quite often that behavior involves gaining a substantial amount of altitude (at least by default), which at an airport is actually probably worse than dropping.
[1] https://www.electronics-notes.com/images/antenna-yagi-radiat...
That's the part that seems unadvisable near an airport.
Privacy violations using drones are another issue that will promote the development of such guns/systems.
Here's a great article that mentions one such system that can hijack drones mid-air: http://www.whatafuture.com/drone-hijacking-device-takeover-t...
Or DJI could track these drones themselves from the mothership, uploading the day's GPS history every time they call home... not sure if/why they don't already do this. Would eliminate much of the need for a bounty.
"Good morning. In less than an hour, aircraft from here will join others from around the world. And you will be launching the largest aerial battle in this history of mankind..."
The issue is scale. These guns can likely be deployed for big events etc but how do you effectively protect the airspace around airports, powerplants, or other critical infrastructure with such devices?
Use cameras, acoustic sensors, and RF receivers to detect a drone's presence, and use a phased array antenna to shit some appropriate jamming signals in its general direction.
Your local electronic warfare military contractor should be able to set you up with all the equipment you need for such a system.
I've read about training birds of prey to kill drones, seems dangerous for the bird to me though.
Joke aside, is not far from being a real tactic, deploying the so-called "defender" drones, which are guided by a autonomous system, fed by an array of sensors around the perimeter.
I can see myself developing such a system.
DJI is going really far on this. They already have pre-installed software which restricts drones in no-fly zones. Even more, they are putting out a bounty program to that. I heard that there are some special electrical guns which can shoot down drones. It might be useful to deploy these in no-fly zones.