RFID 101

Radio frequency identification (RFID) is a generic term that is used to describe a system that transmits the identity (in the form of a unique serial number) of an object or person wirelessly, using radio waves.  These wireless systems allow for non-contact reading and are effective in manufacturing and other hostile environments where traditional identification technologies such as bar code labels could not survive.  RFID tags can also act as electronic data carriers that can be read and written to throughout their journey.  It's grouped under the broad category of automatic identification (AutoID) technologies.

Auto-ID technologies include bar codes, optical character readers and some biometric technologies, such as fingerprint scans. Auto-ID technologies have been used to reduce the amount of time and labor needed to input data manually and to improve data accuracy.

A typical RFID tag consists of a microchip attached to a radio antenna mounted on a substrate. The chip can store from as little as 64 bits to as much as 2 kilobytes of data. For example, information about a product or shipment—date of manufacture, destination and sell-by date—can be written to a tag.

To retrieve the data stored on an RFID tag, a reader is required. A typical reader is a device that has one or more antennas that emit radio waves and receive signals back from the tag. The reader then passes the information in digital form to a host computer system.