What is ........ RFID?

What is it?

Is an abbreviation for Radio Frequency Identification.

rfid device
Courtesy of Wikimedia Commons

This is a term used to describe a type of wireless technology used to identify objects, animals (or people).

What does it look like?

A typical RFID device is shown in the photo opposite alongside a grain of rice. It is tiny.

There are two parts to the system.

1. The tag.
The simplest version is a tiny microchip that contains a code identifying the thing to which it is attached / glued to.

The microchip is often connected to a flat spiral aerial that allows it to work by radio signals.

2. The Reader.
This machine sends a radio signal to the tag asking for its code. The tag senses the request and sends back its unique code. The reader can then connect to a computer or database and uses the code to identify what the object is (or the identity of the person the tag is attached to).

The system works over a foot or so, which is fine when the tags are guaranteed to be close to the reader.

The handy thing about the tag is that it needs no power at all - no battery needed. This is because the reader sends it enough radio power to turn on whilst it is being interrogated.

Are there other types of RFID?

Yes, the no-battery versions are great for cheap, non-critical tags as might be used in a book-sleeve or shirt package.

But if it is really important to have reliable identification then there are more expensive and larger battery-powered versions. These use higher radio power and so they transmit over a much greater distance (100's of metres).

These kind of tags are used for very expensive items such as military stores or toll booth systems where you will be charged for using a road or rail system.

Who uses it?

1. Businesses that want to keep track of their stock as it moves from one place to another.
For example, many parcel delivery companies now offer the ability for you to check where your parcel is as it is being delivered. They can do this by attaching an RFID tag on the parcel, then a reader at each main point of its journey keeps track of its progress.

2. Security systems that can sense the identity of the person wanting access to a restricted area.
The person wears an RFID tag, so when they approach a reader, it can request an identity check without the person having to do anything.

3. Anti-theft
Many shops use RFID to deter shop-lifting. Have you noticed some shops have some tall objects standing either side of the doors? You have to walk between them in order to leave the shop. This is part of an RFID system. Many of the more expensive items in the shop will have hidden RFID tags. If you try and walk out of the shop, the Readers either side will request the tag for its code - that code is checked against a database to see if it has been paid for yet. If not, the alarm sounds. Another reader is located beneath the desk by the till. As you pay, they slide the object over the reader to register it is as having been been paid for.

4. Passports.
Many countries, including the UK now use RFID tags inside passports. The tag not only identifies the person, but also stores a digital photograph and a record of their movement in and out of the country. In order to reduce the chance of someone 'skimming' that information, the passport contains a metal film to prevent them being read when closed.

Video News

See the BBC news items on RFID here

See the BBC videos on RFID here

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