How Radio Frequency Identification Works

Nowadays, most shopping malls and supermarkets use the Universal Product Code in order to identify a certain product, albeit the use of the bar code implies that all shoppers must stand in line to have the bought products scanned, which also requires a lot of time and patience, something not all costumers have. The Radio Frequency Identification may resolve this little problem, since products bearing RFIDs can be tracked with the help of radio waves.

Shopping could become an experience as simple as filling your cart with products and going straight home. The basic idea is that the RFIDs would be connected through an electronic reader to a large network, and the information associated with that product would be sent to the retailer and the manufacturer, so that the bill is registered and paid automatically from your bank account.

The UPC bar code was invented in the 1970, as a means to gather information related to the price and quantity of a product or even how bought the respective product was. However, soon after it was first introduced in supermarkets, the designers discovered that their invention had some disadvantages. Such as the fact that each product must bear a bar code, be scanned and, last but not least, the bar code is read-only technology.

At the same time that the UPC bar code appeared, the RFID technology started to make itself noticed and used for cow or luggage identification. Originally, they were called inductively coupled RFID tags, because the metal coils and antennae system could create a magnetic signature that was deciphered by a RFID reader. Alternatively, capacitively coupled tags used conductive substances instead of metal coils in order to create less expensive tags.

In the end, RFID tags came to use silicon chips to store data, thus overcoming the read-only limitations imposed by the UPC bar code. Most of the time, the silicon chip of a RFID tag is in stand-by. As it is read, it starts to send information via radio waves, whether by using power from an internal battery or by harvesting part of the electromagnetic waves used to read it. The reader receives the radio waves sent by the RFID tag and identifies them.

RFIDs may be active, semi-passive and passive. The active and semi-passive RFIDs are powered with the help of internal batteries, however while active tags send radio waves to the reader, semi-passive tags need to be activated by radio waves from the reader in order to broadcast information. Both are generally very expensive, mostly because they are able to send information to distances up to 30 meters.

Passive RFIDs, on the other hand, rely solely on power provided by the reader and are effective over distances up to 6 meters.

Today, RFIDs are used in electronic passports, human and animal tracking or human chipping, as medical databases. Nonetheless, RFID chips are not extremely popular amongst people, mostly because of general fear that RFID chips may one day become mandatory.



MORE RELATED ARTICLES: Ultra-efficient Nuclear Fuels, too Unstable for Use The Earth Like an Electric Circuit Stress and Cocaine The Oldest People in North America: 14,300 Years Old New Technique Peeks Inside Opaque Amber Meteor Shower Spotted on Mars Astronomers Look Back into the Universe's Past Compressing Stellar Cores