RFID systems:

Now chip cards, and, perhaps more particularly, smart cards, are widely used in large parts of the world in a variety of applications, communications engineers have come up with another one: Radio Frequency Identification (RFID) readers. In this application, chipcards are used in conjunction with resonant circuits (antennas), but wireless and without physical contact, for the identification of persons, animals, objects or for process control. The technique is not new, but the means of applying it is.