There are mainly Three (03) different types of RFID Tags:
They are:
- Passive RFID tags
- Active RFID tags
- Semi-passive RFID tags
Active RFID tags:
Some Active Tags
Active RFID tags have their own internal source of power. This is used to
power the circuits and broadcast signals to the reader. These tags are
usually more reliable than passive tags. They also have a stronger signal
because of their built-in power supply. This also allows them to work in
places that passive tags wouldn't be able to, such as in water(which would
incluce humans and other animals), metal, or from longer distances. They are
however, larger and more expensive than passive tags. Today, active tags can
transmit from hundreds of meters and their batteries can last for about 10
years. Some active tags contain different sensors that can read things like
temperature, humidity, and radiation.
Passive RFID tags:
Passive RFID tags don't have an internal source of power. There is an
electrical current that is created in the antenna by the incoming radio
frequency signal from the reader. This means that the antenna has to be able
to collect power from the incoming signal and also transmit the outbound
signal to the reader. A passive tag can respond with identification numbers
or non-volatile storage data. It can be read from about 10 cm to a couple of
meters and since they don't have to have a power source on the device, they
can be extremely small(they can be embedded in a sticker or under the skin).
In 2007, a company called RFIDsec created a passive tag that had many more
privacy capabilities built into the device. These included built-in firewall
acces controls, communication encryption, and a silent mode that would ensure
that the soncumer at the point of sales can get exclusive control of the key
to control the tag. In 2007, Hitachi,Ltd. developed a passive tag that was
table to embedded in a sheet of paper. The problem with this is the antenna
is 80 times bigger than the device. It can receive and send signals from as
far away as a couple hundred meters. Companies are currently developing
methods of production that will hopefully lower the prices of RFID tags
dramatically.
Semi-passive RFID tags:
 |
| Semi Passive Tag |
Semi-passive tags have an internal power source like active tags, but it
only powers the integrated circuit and doesn't broadcast a signal to the
reader. The radiofrequency is used to broadcast a signal like a passive tag.
These tags have a higher sensitivity than passive tags. This means that they
can have a higher range and enhanced reliability. They also have a longer
battery life than active tags. Information from www.wikipedia.org/wiki/RFID.