Scientists in China have showcased a microwave-powered system capable of transferring wireless energy to drones. This technology uses a ground emitter to recharge unmanned aerial vehicles, even while both components are moving.

A vehicle that can zap energy into a fleet of drones, allowing them to fly indefinitely, is getting closer to becoming a battlefield reality. 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. Some analysts have likened the concept to a “land-based aircraft...