Broadcasting, (at least here) means transmission through air. So some means needs to be provided to launch our carefully constructed modulation into the air (transmission medium). There many ways to do this both by electrical and magenetic priority simulation of the ether, simple dipoles, yagi, frame box´s, cylinders, patches, horns, slots. In fact anything stuck up in the ether will couple something. (Well LED RAM memories are an exception)
In this section we look at some dipole...yagi used for RF emissions
Those corkscrew wire frames that sent those signals to the moon.