Radio Frequency Identification Systems:
Active And Passive Rfid Tags
Active and Passive RFID Tags:
There are primarily two types of RFID tags. One is active
and the other is passive. An active tag is powered using
internal battery, where a passive tag gets energized using
a the power from a tag reader. A passive RFID tag will not
have a battery or any kind of power source by itself. It
extracts the required energy from a reader. Hence, a passive
RFID tag reader must be able to emit stronger electromagnetic
signals, and in return, identify very weak signals from
the passive RFID tag.
Given below are the primary differences between a Passive
and Active RFID tags:
||External (Reader provided)
||Only within the area covered by the reader,
typically up to 3 meters.
||Can provide signals over an extended range,
typically up to 100 meters..
||A passive tag is energized only when there
is a reader present.
||An active tag is always energized.
|Magnetic Field Strength
||High, since the tag draws power from the
electromagnetic field provided by the reader.
||Low, since the tag emits signals using internal
||Very high, ideally does not expire over
a life time.
||Limited to about 5 years, the life of a
||Limited data storage, typically 128 bytes.
||Can store larger amounts of data.
||Slightly bulky (due to battery)