"Roger Hayter" wrote in message
...
John Rumm wrote:

On 21/08/2019 13:16, dennis@home wrote:
https://www.bbc.co.uk/news/business-48859331

Someone really should tell them that the normal RFID tags in use are
not
powered by radio waves.

You do know what the RF in RFID stands for don't you?

Radio frequency does not necessarily imply radio (electromagnetic)
waves. In fact, if you have an RF magnetic field generated there will
be some EM radiation around. But I believe if is purely the near field
magnetic induction at RF that excites the tag.

Doesn’t explain the obvious RF antenna in the pic someone posted.
That’s not a coil.

I also believe, but my knowledge is limited, that RF excited tags
exist for some purposes, but are not the common ones. ICBW