And so, the makers of drones will begin hardening the drones to EMP and other microwave energy through the use of shielding, which likely have been incorporated within state developed drones (i.e. China, Russia, etc). In designing circuitry for complex electronics, it is electrical engineering 101 to provide for the proper shielding one would expect in the environment in which the circuit is supposed to be exposed. A longer term approach might be to cause the sensors within such a drone to be “blinded” to navigation. GPS jamming, RF jamming techniques, IR and laser scattering/jamming. It’s going to be a long slog in developing electronic jamming/counter-jamming for these drones, for many years to come. Directed energy would certainly be an arrow in the quiver of a variety of systems that will need to be developed/fielded.
Any shielding on a drone will block the communications signals they need for control. If they are a self-contained robot, like a cruise missile, I am not sure a light-weight Faraday cage can be designed to protect them. Don’t Faraday cages need to have an earth ground?
For a look at the new world of microwave EMP, go here:
https://www.popsci.com/china-microwave-weapon-electronic-warfare