The RFID Technology
RFID allows data to be
transmitted wirelessly by anything containing an RFID
tag. This is read by an RFID reader which can feed into
a host computer system. The power of RFID stems from the
fact that no contact or even line-of-sight is needed to
read data from an RFID tag.
RFID tags are really tiny
microchips with memory and an antenna. RFID tags detect
radio signals sent by an RFID reader and respond by
transmitting a unique code, or other data, back to the
reader. There are two type of RFID tags.
Passive RFID tags do not
require batteries and can be no more than 0.3mm in size.
They draw their power from the radio signal sent out by
the RFID reader. Passive tags are normally read-only
i.e. the data they contain cannot be changed.
Active RFID tags are
powered by a battery and contain a transmitter that is
always on. They are much larger than passive RFID tags
but have a longer range and may contain a read-write
memory.
RFID readers, or
interrogators, detect RFID tags and obtain the
identification, location, and any other information that
may be embedded in the tag.
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