Radio Frequency IDentification has been around through most of modern history since World War II.

During the war, the British developed the Identify Friend or Foe (IFF) system, which consisted of a transmitter inside aircraft.

When the aircraft received a special signal from the ground, the transmitter would automatically turn on, sending a response signal and identifying the aircraft as a friend.

The Germans had a similar concept, though much simpler, in which pilots would invert their aircraft when approaching the airfield, which changed the radio signal reflection.

Radio frequency energy continued to be studied and advanced upon after the war and the idea of using them to identify objects from afar was expanded upon.

By the late 1960s, companies were already using electronic surveillance tags to mark items as purchased or not.

These simple one-bit tags were either “on” or “off” and could be switched one way or the other at the sales counter.

These simple systems are still in use today in all kinds of retail applications as a basic security measure to protect the store's more valuable goods.

In 1973, a man named Mario Cardullo received the first patent for an active RFID tag with rewritable memory.

This marked a turning point in the history of RFID as the tags could now be used to track individual items as well as being used for security purposes.

So not only could the tag identify the idem as an individual piece through a recorded ID, but also be switched “on” and “off” like the old security tags without losing its memory.

Charles Walton, that same year, received a patent for a transponder used to unlock a door