RFID Tags

Radio Frequency Identification, popularly called as RFID, is an automatic identification technique that makes use of RFID tags.  Data is stored and retrieved using RFID tags or transponders. Basically, an RFID tag is an item or a device that can be affixed to a product to identify it with the help of radio waves. Tags can also be embedded in a person or an animal to know about its whereabouts. Tags and tag readers, transponders, transceivers, transmitters and receivers, middleware or application software are some of the commonly known and broadly used components of an RFID system.

What is an RFID tag?

An RFID tag is a microchip pooled in with an antenna in a compacted enclose; the packaging is planned to permit the RFID tag to be attached to a thing to be tracked. RFID tags can be very diminutive like the dimension of a large rice grain. Others may be the size of a little paperback book. The tinier an RFID tag is, the better. Some tags can be as small as 1/3 of a millimeter across. One can notice and must have seen such tiny RFID tags while out shopping in a grocery store attached to a food packet or hidden between the pages of a book in a bookstore or tagged to a pair of jeans. These RFID tags have been placed there with the purpose of preventing theft and reducing cases of shoplifting. So, if a miscreant thinks of pocketing a valuable item, he will not get past the security door as the tag will connect to the tracker and will alert the shop by beeping the alarm system. Such applications have also made even government departments interested in RFID tags.

On the whole there are two types of RFID tags:

1. Active RFID Tags
2. Passive RFID Tags

Also, there are chip-based RFID tags, which contain silicon chips and antennas.

How does an RFID tag function?

The RFID tag's antenna receives signals from an RFID reader or scanner and then replies back to the signal, more often than not with some supplementary information (something like a distinctive serial numeral or extra, customized information. These chips act as transponders (transmitters/responders), always on alert in case a radio transceiver, or RFID readers are sending signals. When a transponder besotted by a particular radio inquiry, it replies by transmitting its unique ID code, possibly a 128-bit number, to the transceiver. Most RFID tags don't have batteries. However, an Active RFID tag has its own internal power sourcewith an average battery life of up to 10 years. On the other hand a Passive RFID tag operates by using the power from the RFID transceiver. It depends on the RFID reader for power.

Nearly all of these ‘radio conversations between a tag and reader’ are intended to be read or interpreted between a few inches and quite a few feet away. This depends on the size of the antenna and the energy driving the RFID tags. However, it is possible to increase that distance if a more sensitive and powerful RFID receiver is built.

What Are Zombie RFID Tags?

One of the main worries about RFID tags is that their contents can be read by anyone with an aptly operational scanner - even after the buyer takes it out of the store. The technology that has been recommended to save the customer this hassle and anxiety of being tracked is a ‘zombie RFID tag’, a tag that can be disabled or deactivated for the time being when it leaves the store. The course of action would be like the customer bringing up his or her purchase up to the cash or check register after which the RFID scanner reads the item. This followed by payment and as the tag leaves the store, a special mechanism sends a signal to the RFID tag to "die." That is, it can be readable no more.

The "zombie" factor is introduced when an item is brought back to the store. An exceptional mechanism particularly designed for that type of a tag "re-animates" or “brings back to life” the RFID tag, permitting the object to reenter the supply string.
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RFID tags prices are nearly up to 50 cents, but prices are plummeting. Just the once they get to be 5 cents each, it will be cost-efficient to put RFID tags in more or less everything that overheads a cost of more than a dollar.