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URL:
http://www.usingrfid.com/
RFID (radio frequency identification) is a technology
that incorporates the use of electromagnetic or electrostatic coupling in the
radio frequency (RF) portion of the electromagnetic spectrum to uniquely
identify an object, animal, or person. RFID is coming into increasing use in
industry as an alternative to the bar code. The advantage of RFID is that it
does not require direct contact or line-of-sight scanning. An RFID system
consists of three components: an antenna and transceiver (often combined into
one reader) and a transponder (the tag). The antenna uses radio frequency waves
to transmit a signal that activates the transponder. When activated, the tag
transmits data back to the antenna. The data is used to notify a programmable
logic controller that an action should occur. The action could be as simple as
raising an access gate or as complicated as interfacing with a database to
carry out a monetary transaction. Low-frequency RFID systems (30 KHz to 500
KHz) have short transmission ranges (generally less than six feet).
High-frequency RFID systems (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) offer
longer transmission ranges (more than 90 feet). In general, the higher the
frequency, the more expensive the system.
RFID is sometimes called dedicated short range
communication (DSRC).
Keywords:
RF, ID, RFID
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