I agree it is a really really stupid name. But its been around for a while, and clearly it is supposed to describe its function of turning RF-AC into DC.
Usually *quite* modest amounts of power (but evidently in the 30s enough to power a model helicopter)
You can find out a lot of stuff on it using that name. If you don't use it you'll likely find little of interest. Just the usual 'energy harvesting' borderline nut cases.
They also have optical 'rectennas' now that are still quite inefficient but which are a new form of PV cell, basically. And they have potential to improve quite a bit.
As the amount of power available is very low (microwatts now, milliwatts eventually) but with that caveat, will be found in abundance almost everywhere where there are 5G radio transmitters, which will be almost everywhere because it will be a mesh network, with individual devices having a peer to peer function to extend the network.
This is all still in the design phase, as far as I can tell.
This long term low power use - where the incident RF is tapped to power sensors, and networking, (otherwise what would be the point of having sensors if they could not communicate) seems to be one of the use cases that designers are planning for. A 15 year design life seems reasonable for a machine to machine only sensor in a consumer device.
Read the literature. the 5G system will operate from 600 MHz to 71 GHz, and the bandwidth occupied by individual transmissions will be very high. Also the number of different 'users' (networked devices) in a given area could be up to 1,000,000 devices per km2. (See R. E. Hattachi and J. Erfanian, "A Deliverable by the NGMN Alliance NGMN 5G white paper," Feb 17, 2015)
The security of the system will have to be very high because a great deal of sensitive data will be carried by it, including health information and machine to machine communications. Its latency will also be very low. This will require as I said, a significant amount of power as well as active beam forming.
If the capability is there, hobbyists will be making use of it too, I'm sure. or at least the power from it.
So this is a serious post.
As far as the name goes, its pretty old. Its been around for quite a while. I certainly didn't make it up.