An RFID tag that doesn't depend on a silicon microchip to store information. Some chipless tags use plastic or conductive polymers instead of silicon-based microchips. Other chipless tags use materials that reflect back a portion of the radio waves beamed at them. The unique return signal can be used as an identifier. A computer takes a snapshot of the waves beamed back and uses it like a fingerprint to identify the object with the tag. Companies are experimenting with embedding RF reflecting fibers in paper to prevent unauthorized photocopying of certain documents. Chipless RFID tags can be used in many different environments than RFID tags with electronic circuitry. They tend to work over a wider temperature range; these tags also are less sensitive to RF interference.
Chipless tags are sometimes used in anti-counterfeiting with documents. However, since the tags cannot transmit a unique serial number, they are less usable in the supply chain.