Only tricky thing is if currents induced in motors are too hard to reject in driver circuitry, tho even at the extreme this should be possible to insulate with capacitors (or worse/heavier with transformers)
It wouldn't, the only way to "shield" from magnetic fields is to get them to induce Eddy currents and but that requires more and more length and as the wavelength gets longer and essentially infinite for the Earth's field which is very slow moving.
> RF ground up there. "ground" is relative and not at all required for a Faraday cage to work.
The advantage of microwaves is that unlike lasers, kilowatt strong microwaves are easy to generate, it is an incredibly well studied problem, because that's how early radar systems worked. They are what secured the skies above London against the Nazi air force.
Israel seems to be trying another approach with lasers. They decided it doesn't matter if the laser is powerful, if you just have hundreds of 2W lasers aimed at the same target.
And all that stuff is a new supply chain and more weight which isn't payload.
That a countermeasure can be built doesn't mean it's necessarily effective to do so - your drones get less cheap, less numerous, you have to incorporate such systems into tactical and strategic planning.
"That a countermeasure can be built doesn't mean it's necessarily effective to do so" applies especially to reading a corporate press release about a system doesn't even have a timeline for being on the battlefield.
cluster heads solve this beautifully because 1kg of high explosive kills everything good enough in 5 meters radius.
For comparison, the Excalibur GPS guided artillery shell was considered precision because it would hit within 5m reliably.
Compare to the lethal range of a 155mm, where the kill radius is 50m and casualty at 100m.
Many of the drones in the Russia-Ukraine war are powered by ICEs. I'm thinking of Ukraine's long range drones presently deleting Russia's refinery distillation towers, fixed radar installations, parked aircraft, ammo dumps, etc.
Those engines are not purely mechanical, but purely mechanical engines have been widespread and are still commonplace today. A 2-stroke diesel being one example, but even gas turbines can be purely mechanical. So one can imagine such an adaptation in response to microwave countermeasures.
You also need to think through your cooling solution. Enclosed batteries, converters and motors will generate a lot of heat over typical mission, and you don't have the benefit of direct air cooling anymore.
At just a few GHz, metal mesh ought to be adequate for the cage material, so cooling isn’t necessarily a huge problem.