White Paper: The Technology Of On-Metal RFID

Radio Frequency Identification, or RFID, is a method of communicating using radio waves. Just as radio signals can travel through the walls of your home to your radio, radio waves can communicate between an RFID tag and an RFID reader without requiring line-of-sight visibility.

RFID systems are used to send an identification signal from a tag to a reader. RFID tags have two parts: a silicon chip, which stores a small amount of data, and an antenna, which receives and transmits radio frequency (RF) signals. When an RFID tag receives a signal from an RFID reader, it returns a modified version of the reader's radio waves, communicating the data it has stored. In basic systems, the information stored on the chip is a unique identification number. Hence, Radio Frequency Identification, or RFID.

This simple but clever technology was first developed as an offshoot of transponder and covert listening device technology used during World War II. The first patent for RFID technology was issued in 1973. Early RFID tags were large, complex devices made of metal-coiled antennas and glass. Over the ensuing 35 years, many improvements were made to RFID technology. The miniaturization of silicon chips, the increase in their data storage capacity, and the ability to manufacture very inexpensive printed, etched, or stamped antennas have all contributed to much smaller, more portable, and far less expensive RFID tags.