The term Radio Frequency Identification is used for automatically identifies an object that transmits the identification (in the form of a unique serial number) of an object wirelessly, using radio waves.

Radio Frequency IDentification abbreviated, as RFID is a Dedicated Short Range Communication (DSRC) technology. It is very similar to Barcode identification systems but it got a major difference. RFID does not require line-of-sight access but bar code scanning it is must.
RFID technologies are grouped under the more generic Automatic Identification (Auto ID) technologies. The existing Identification systems are not sufficient for today use as their low storage capacity and the another fact that they cannot be reprogrammed.
A feasible solution is putting the data on silicon chips and contact less transfer of data between the data carrying device and its reader. The power required to operate the data-carrying device would also be transferred from the reader by contact less technology. These all lead to the development of RFID devices.

RFID TECHNOLOGY AND ARCHITECTURE: In an RFID system, the RFID tag, which contains the tagged data of the object, generates a signal containing the respective information, which is read by the RFID reader, which then may pass this information to a processor for processing the obtained information for that particular application.

With RFID, the electromagnetic or electrostatic coupling in the RF (radio frequency) portion of the electromagnetic spectrum is used to transmit signals. An RFID system consists of an antenna and a transceiver, which read the radio frequency and transfer the information to a processing device (reader) and a transponder, or RF tag, which contains the RF circuitry and information to be transmitted. The antenna provides the means for the integrated circuit to transmit its information to the reader that converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to receivers in which it can analyze the data.

Thus, an RFID System would following three components:

RFID tag or transponder

RFID reader or transceiver

Data processing subsystem

The transponder, or RF tag tags can be either active or passive. While the active tags have on-chip power, passive tags use the power induced by the magnetic field of the RFID reader. Thus passive tags are cheaper but it got a limitation that, it work in a limited range (

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