The most common method of generating electromagnetic radiation is by using oscillating charges, for instance in antennas. However, I couldn't think of an example where varying magnetic fields are deliberately used for creating electromagnetic radiation. Things like DC electric motors and generators produce EM radiation as an accidental by-product but it's not really their primary objective. So is there any better example in which a varying magnetic field is primarily used for generating EM waves?

To be more specific I'm looking for examples of sources of EM radiation which are otherwise only sources of magnetic fields (and not electric fields) when stationary.

**Disclosure**: This question was a puzzle posed by our antenna theory professor last week and I'm not sure whether DC motors/generators is the example he is looking for.