We are in the midst of what may become one of the true technological transformations of our time. RFID (radio frequency identification) is by no means a new technology. RFID is fundamentally based on the study of electromagnetic waves and radio, pioneered in the 19th century work of Faraday, Maxwell, and Marconi. The idea of using radio frequencies to reflect waves from objects dates back as far as 1886 to experiments conducted by Hertz. Radar was invented in 1922, and its practical applications date back to World War II, when the British used the IFF (Identify Friend or Foe) system to identify enemy aircraft (Landt, 2001). Stockman (1948) laid out the basic concepts for RFID. However, it would take decades of development before RFID technology would become a reality. Since 2000, significant improvements in functionality, decreases in both size and costs, and agreements on communication standards have combined to make RFID technology viable for commercial and governmental purposes. Today, RFID is positioned as an alternative way to identify objects with the ubiquitous bar code.
Key Terms in this Chapter
Semipassive Tag: This type of tag is similar to an active tag in that there is an onboard battery, which is used to run the microchip’s circuitry and boost the effective read range of the tag. It is also called a battery-assisted tag.
Passive Tag: A passive tag is a type of RFID tag that does not have its own power supply. Instead, the tag draws power from the reader, which sends out electromagnetic waves that induce a current in the tag’s antenna. Without an onboard power source, passive tags have a lesser read range than active tags. However, they cost less than active tags and have an unlimited life span.
Electronic Product Code (EPC): An EPC is a unique number, stored in the chip on an RFID tag, that identifies an item in the supply chain, allowing for tracking of that item.
Automatic Identification (Auto-ID): Auto-ID is a broad term encompassing technologies used to help machines identify objects. A host of technologies fall under the automatic-identification umbrella, including bar codes, biometrics, smart cards, voice recognition, and RFID.
Frequency: Frequency is the number of repetitions of a complete wave within 1 second; 1Hz equals one complete waveform in 1 second, and 1KHz equals 1,000 waves in a second.
Radio Frequency Identification (RFID): RFID is an automatic identification technology that uses radio waves to identify objects.
Active Tag: An active tag is a type of RFID tag that has its own power supply (battery or external power) and, when interrogated by a reader, the tag emits its own signal. Active tags have far greater read distances than passive tags, and they can be combined with sensors to provide information on the environment and condition of the item. They are also more expensive than passive tags and, due to the battery, have a limited life span.
Smart Label: This is a printed label that contains printed information, a bar-code identifier, and an RFID tag. It is considered to be smart because of its ability to communicate with an RFID reader.