| Radio-frequency identification RFID is an automatic | | | | active, or semi-passive (also known as |
| identification method, relying on storing and remotely | | | | battery-assisted). Passive tags require no internal |
| retrieving data using devices called RFID tags or | | | | power source, thus being pure passive devices (they |
| transponders. An RFID tag is an object that can be | | | | are only active when a reader is nearby to power |
| applied to or incorporated into a product, animal, or | | | | them), whereas semi-passive and active tags require |
| person for the purpose of identification using radio | | | | a power source, usually a small battery. |
| waves. Some tags can be read from several meters | | | | Passive |
| away and beyond the line of sight of the reader. | | | | Passive RFID tags have no internal power supply. |
| Radio-frequency identification (RFID) is an automatic | | | | The minute electrical current induced in the antenna |
| identification method, relying on storing and remotely | | | | by the incoming radio frequency signal provides just |
| retrieving data using devices called RFID tags or | | | | enough power for the CMOS integrated circuit in the |
| transponders. | | | | tag to power up and transmit a response. Most |
| An RFID tag is an object that can be applied to or | | | | passive tags signal by backscattering the carrier |
| incorporated into a product, animal, or person for the | | | | wave from the reader. This means that the antenna |
| purpose of identification using radio waves. Some | | | | has to be designed both to collect power from the |
| tags can be read from several meters away and | | | | incoming signal and also to transmit the outbound |
| beyond the line of sight of the reader. | | | | backscatter signal. The response of a passive RFID |
| Most RFID tags contain at least two parts. One is an | | | | tag is not necessarily just an ID number; the tag chip |
| integrated circuit for storing and processing | | | | can contain non-volatile data, possibly writable |
| information, modulating and demodulating a (RF) | | | | EEPROM for storing data. |
| signal, and other specialized functions. The second is | | | | Active |
| an antenna for receiving and transmitting the signal. | | | | Unlike passive RFID tags, active RFID tags have their |
| Chipless RFID allows for discrete identification of tags | | | | own internal power source, which is used to power |
| without an integrated circuit, thereby allowing tags to | | | | the integrated circuits and to broadcast the response |
| be printed directly onto assets at a lower cost than | | | | signal to the reader. Communications from active |
| traditional tags. | | | | tags to readers is typically much more reliable (i.e. |
| Today, RFID is used in enterprise supply chain | | | | fewer errors) than from passive tags due to the |
| management to improve the efficiency of inventory | | | | ability for active tags to conduct a "session" with a |
| tracking and management. However, growth and | | | | reader. |
| adoption in the enterprise supply chain market is | | | | Semi-passive |
| limited because current commercial technology does | | | | Semi-passive tags are similar to active tags in that |
| not link the indoor tracking to the overall end-to-end | | | | they have their own power source, but the battery |
| supply chain visibility. Coupled with fair cost-sharing | | | | only powers the microchip and does not power the |
| mechanisms, rational motives and justified returns | | | | broadcasting of a signal. The response is usually |
| from RFID technology investments are the key | | | | powered by means of backscattering the RF energy |
| ingredients to achieve long-term and sustainable RFID | | | | from the reader, where energy is reflected back to |
| technology adoption. | | | | the reader as with passive tags. An additional |
| RFID tags | | | | application for the battery is to power data storage. |
| RFID tags come in three general varieties:- passive, | | | | |