What Is An RFID Tag?

- May 15, 2018 -

Radio frequency identification (RFID) tags are used in a wide range of applications such as: identifying animals, tracking goods through the supply chain, tracking assets such as gas bottles and beer kegs, and controlling access into buildings. RFID tags include a chip that typically stores a static number (an ID) and an antenna that enables the chip to transmit the stored number to a reader. Some RFID tags contain read/write memory to store dynamic data. When the tag comes within range of the appropriate RF reader, the tag is powered by the reader’s RF field and transmits its ID to the reader.

RFID tags are simple, low-cost and commonly disposable, although this is not always the case such as reusable laundry tags. There is little to no security on the RFID tag or during communication with the reader. Any reader using the appropriate RF frequency (low frequency: 125/134 KHz; high frequency: 13.56 MHz; and ultra-high frequency: 900MHz) and protocol can get the RFID tag to communicate its contents. (Note that this is not true of car keys which contain a secure RFID tag.) Passive RFID tags (i.e., those not containing a battery) can be read from distances of several inches (centimeters) to many yards (meters), depending on the frequency and strength of the RF field used with the particular tag. RFID tags have common characteristics, including:

Low cost designs and high volume manufacturing to minimize investment required in implementation.

Minimal security in many applications, with tags able to be read by any compatible reader. Some applications like car keys do have security features, most notably provisions to authenticate the RFID tag before enabling the ignition to start the car.

Minimal data storage comparable to bar code, usually a fixed format written once when the tag is manufactured, although read/write tags do exist.

Read range optimized to increase speed and utility.

RFID card reader 

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