Scientists in China have demonstrated a wireless power transmission system that uses a ground-based microwave emitter to beam energy to an antenna array mounted on the aircraft’s underside. Importantly, they were able to do this while both the drone and charging system were in motion.
In tests, the car-mounted system kept fixed-wing drones in the air for up to 3.1 hours at an altitude of 15 metres (49 feet). The key challenge that the team overcame was maintaining alignment between the emitter and the drone during flight, wrote Song Liwei, the project’s leader.



I have no knowledge in this and it’s early, but what happens to birds in the medium in between the receiver and emitter?
This can’t be good for them.
Nothing. It’s non-ionizing radiation.
Microwaves ovens work by using extreme amounts of energy concentrated into a very small area.
Microwave beams for energy transmission are different.
We’ve known this since at least 1996 when the first paper talking about it was published.
https://www.sciencedirect.com/science/article/abs/pii/0038092X95000834
The biggest obstacle for it is actually RFI.
Edit to add, and here’s a NASA paper from the 1980s talking about it
https://ntrs.nasa.gov/citations/19800010018
I think it’s worth saying that while not ionizing, high power high gain RF can cause damage via burns. Not sure how much power/gain is used in this situation though. Staying away from unfamiliar transmitting antennas is in general a good thing.