Radio-frequency identification(RFID) is the use of a wireless non- contact system that uses radio- frequency electromagnetic fields to transfer data from a tag attached to an object, for the purposes of automatic identification and tracking.
Basic of RFID work• Data- stored within an RFID tags microchip waits to be read.• The tags antenna receives electromagnetic energy from an RFID readers antenna.• Using power from its internal battery or power harvested from the readers electromagnetic field, the tag sends radio waves back to the reader.• The reader picks up the tags radio waves and interprets the frequencies as meaningful data.
Passive RFID• Don’t have battery, and powered by the electromagnetic fields used to read them.• Passive tags are read up to 20 feet (six meters) away.• Really low cost of production between 7 and 20 cents.• As, they haven’t got battery, they haven’t got expiry date.
Semi-Passive and Active RFID• Has internal battery to power circuits.• Use broadcast high frequencies from 850 to 950 MHz that can be read 100 feet (30.5 meters) or more away. With additional batteries this distance can be increased up to 100 meters.• Mostly batteries are working for 10 years.
Types of storage of information• Read-Write – data can be added to or overwritten.• Read-only – you can only read data.• WROM (Write once, read many) – they can have additional data added once, but after they can not be overwritten.