Tech Primer

RFID

What is RFID?

Radio frequency identification, or RFID, is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods to implement this technology, but the most common among them is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna (the chip and the antenna together are called an RFID transponder or an RFID tag). The chip transmits the identification information to a reader via the antenna. The reader converts the radio waves reflected back from the RFID tag into digital information which can then be passed on to computers that can make use of it.

How does an RFID system work?

An RFID system consists of a tag, which is made up of a microchip with an antenna, and an interrogator or reader. The reader sends out electromagnetic waves. The tag antenna is tuned to receive these waves. A passive RFID tag draws power from field created by the reader and uses it to power the microchip’s circuits. The chip then modulates the waves that the tag sends back to the reader and the reader converts the new waves into digital data.

What are the pros and cons of passive and active tags?

Active RFID tags have a battery which is used to run the microchip’s circuitry and to broadcast a signal to a reader. Passive tags have no battery and draw power from the reader. Active and semi-passive tags are useful for tracking high-value goods that need to be scanned over long ranges.

Is RFID better than bar coding?

The big difference between the two is that bar codes are a line-of-sight technology. A scanner has to see the barcode to read it, which means that the people who scan have to position the barcode towards a scanner for it to be read. RFID tags do not need line of sight. RFID tags can be read as long as they are within range of a reader.

Will RFID replace bar codes?

Since bar codes are inexpensive and effective for certain tasks, it is likely that RFID and bar codes will co-exist for many years. Until now, RFID has been too expensive and too limited to be practical for many commercial applications. But if tags can be made cheaply enough, they can solve many of the problems associated with bar codes. Radio waves travel through most non-metallic materials, and can be embedded in packaging or encased in protective plastic for weather-proofing and greater durability.

If RFID is so great, why have not many companies been implementing it?

Because existing RFID systems use proprietary technology, tags of one company cannot be read by another if they do not use systems from the same vendor. Some organisations have come forward to address this issue by developing standards for specific applications. The International Organisation for Standardisation (IOS) is working on standards for tracking goods in the supply chain using high-frequency and ultra-high frequency tags. Another organisation, EPCglobal, has its own process which was used to create bar code standards. Yet another issue hampering adoption of RFID systems has been cost. Currently, RFID readers typically cost upwards of $1,000. Since large companies would need thousands of readers to cover their huge manufacturing plants, warehouses and stores, the cost of deployment would be enormous.

Who is using RFID?

Today, some of the world’s largest businesses and multinational corporations, including giants such as Wal-Mart, Gillette, Coca-Cola and Proctor & Gamble, are developing plans to deploy solutions based on RFID to monitor their global supply chains.

For more information go to http://www.rfidnews.org/