RFID – Radio Frequency Identification
RFID stands for Radio Frequency Identification and is a contactless technology based on the principal of the magnetic field. It supports low frequency (125/134.2 kHz), high frequency (13.56 MHz) and ultra-high frequency (between 300 MHz and 3 GHz) radio waves and is used for data transfer. It consists of an information carrier (RFID tag or RFID card a.k.a. transponder) and a reading device (RFID reader or RFID scanner). When the fields of one of those elements is within the reach range of the other, they can communicate. Furthermore there are two types of RFID tags: passive and active. The latter ones can actively broadcast signals in order to try to connect to a RFID reader in their proximity, whereas passive RFID tags receive their power only when they are situated within the range of a radio frequency field beamed by a RFID reader.
RFID is used in a wide range of applications including but not limited to access control, material tracking, wireless payment, time attendance, inventory control, medical & gym equipment etc. Compared to other identification methods (i.e. barcode) it offers many advantages such as speed, identification of moving objects, easy installation & integration, simultaneous tracking of multiple items, no special positioning or optics needed.
A RFID electromagnetic field can have a range between a few centimeters and a couple of meters depending on its wave frequency and power consumption.