The current limiting factor of small drones is battery capacity. Blade shielding could be used as a microwave pickup antennae and the drone could be charged in flight.
Of course circuitry and design would have to change for a microwave rich environment also some materials and extra circuitry would add a small amount of weight. The drone would be completed by having a real-time battery status to ask for a microwave shot as needed.
Probably, if alone, an autonomous hover mode would be needed to allow for the dropping of the controller to pick up the charging gun. So not quite on the fly. Also, if out in the field a portable power source rather than mains supply will have to supply the gun with what is needed. Microwaves aren't cheap.
The problem I see now is drones won't be the problem but rather people running around with portable directional microwave guns. If the planet hasn't got enough energy in wrong forms.-- wjt, Dec 24 2018 Given the mass and bulk of cavity magnetrons and their associated power supplies, they aren't going to be running very fast.-- 8th of 7, Dec 24 2018 That's what the gas guzzling 4X4 is for.-- wjt, Dec 24 2018 A small not-metal tank of water and a lightweight condenser. Microwaves zap the water, etc.
Could go on the fly (no pun intended) in the UK due to water falling from the sky 397 days a year.-- not_morrison_rm, Dec 24 2018 I'm not sure how much power ground radar at, say, Gatwick puts out, but it might help.-- MaxwellBuchanan, Dec 24 2018 Kilowatts, but the PRF is high, the beam is narrow and constantly moving, and the wavelength is chosen (for obvious reasons, if you had thought about it for a moment) so as to avoid the atmospheric absorption maxima, particularly for water.
A dipole antenna array would harvest some energy, but not a useul amount in terms of sustaining a drone in flight.-- 8th of 7, Dec 24 2018 It occurs to me that overhead power lines are generally not insulated.-- scad mientist, Dec 28 2018 "Man, your drone has some features. That's some heavy looking insulation there, and why are the skids so far apart?... Is that a Jacob's ladder?"-- wjt, Dec 28 2018 // overhead power lines are generally not insulated //
Hmmm ... free energy.-- 8th of 7, Dec 28 2018 random, halfbakery