To completely understand RFID it’s important to understand how Radio communication occurs, RF (Radio Frequency) communication occurs by the transference of data over electromagnetic waves. By generating a specific electromagnetic wave at the source, its effect can be noticed at the receiver far from the source, which then identifies it and thus the information.
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.
The main components of the RFID System can be visualized as the following three components namely:-
- RFID TAG or TRANSPONDER
- RFID READER or TRANSRECEIVER
- DATA PROCESSING SUBSYSTEM
An RFID tag is composed of an antenna, a wireless transducer and an encapsulating material. These 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 with lower range (<10mts) and more sensitive to regulatory and environmental constraints, as compared to active tags.
An RFID reader consists of an antenna, transceiver and decoder, which sends periodic signals to inquire about any tag in vicinity. On receiving any signal from a tag it passes on that information to the data processor.
The data processing subsystem provides the means of processing and storing the data. RFID systems can also be differentiated based on the frequency range it uses. (Described in the later chapter) Standards are critical in RFID (described later as well) be it payment systems or tracking goods in open supply chains. A great deal of work has been going on to develop standards for different RFID frequencies and applications.
RFID standards deal with the following:-
- Air Interface Protocol – The way tags and readers communicate
- Data Content – Organizing of data
- Conformance – Tests that products meet the standard
- Applications – How applications are used
Types of Tags
RFID tags can be either
- Semi-passive (also known as semi-active )
For more information, see: