What is an RFID Tag?

Michael Anissimov
Michael Anissimov

Radio Frequency Identification (RFID) Technology uses small electronic tags as wireless identification devices. Passive RFID tags require no standard power source, but rather use an antenna to pick up just a little bit of power and transmit a response back to a receiver. The technology dates back to at least 1945, but it has only begun to achieve popularity and financial feasibility in the first years of the 21st century.

RFID tracking systems are installed in intermodal containers to keep track of their movements.
RFID tracking systems are installed in intermodal containers to keep track of their movements.

An RFID tag has just a little bit of information about the object it is attached to. If you tagged everything in your home, you could walk around your house with a receiver and point it at any object, and the receiver would tell you what you're pointing at. The technology works even if there is an intervening medium between the tag and the receiver.

A RFID tag is a means to store electronic data on an item that can be easily accessed later with a RFID reader.
A RFID tag is a means to store electronic data on an item that can be easily accessed later with a RFID reader.

RFID tags are on the edge of breaking into the shipping industry. It has been proposed that every crate be tagged to permit easy and automated identification. If made ubiquitous, the technology would vastly streamline the shipping process. It has been said that the cost of a single tag will need to drop below 5 US cents for their widespread use to become cost-effective.

In 2006, major credit card companies started offering cards with implanted RFID technology, allowing the card to be used without a magnetic reader. Some bottles of medication come with RFID tags, allowing blind seniors to identify their contents and expiration date. These tags have been installed for automated payments of all kinds, such as payments on toll roads.

The smallest RFID tags are only 0.15 mm × 0.15 mm, but they must be attached to an antenna which is usually around the size of a postage stamp. People have implanted these tags under their skin which interoperate with household security systems. For example, an RFID cyborg might simply wave her hand in front of a door, causing an built-in receiver to identify her unique tag and open the door.

Along with passive tags, there are also active tags which are slightly larger — about the size of a coin. These tags come with their own power sources and operate at a greater signal strength over longer distances. Active tags have been proposed for use as intermediaries between passive tags and a central reader or computer. Within a few years, there may be hundreds of products in your home that come equipped with RFID tags.

Michael Anissimov
Michael Anissimov

Michael is a longtime wiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

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Discussion Comments


@Mammmood - I agree that miniaturization is a great thing. The most obvious application I can see is tagging products in the store. Have you ever seen those price scanners?

Imagine if those products had RFID tags. You would then have not only have the ability to scan price but also to scan a lot of information about the product, virtually anything you needed to know. I think that it would make asset management and tracking easy too.


@miriam98 - What’s with the cyborg thing? Do we really want people equipped with chips, just so they can wave their hands over security doors? Is opening a door manually such an ordeal?

I hope we keep RFID tagging technologies firmly grounded in reality. I don’t think we need to slip off into the world of science fiction fantasies.

Besides, they already have retinal scanners which do a good job of detecting your unique signature as it were. There’s no need for body implants.


I am excited about the prospects of the RFID chip getting smaller and smaller. This means that there will be no end in sight to the practical applications for such chips, and they will be cheaper to produce as well.

One of the first applications I saw was when I lived overseas. I got a U.S. passport in the late 1990s and it was dubbed the “e passport.” It was a regular passport but it had an RFID chip embedded into it, and the chip contained the basic information that was on the passport.

This made it easy for computers and scanners to pick up the technology. This becomes very useful at port of entry when you want a hassle free experience.

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