Reprinted from the November 2004 issue of
Radio frequency identification (RFID) is becoming familiar around the world -- in toll collections, livestock tracking, supply chain management, automated vehicle identification, and in some places, beneath human skin. And demand is growing. In a 2003 study, Wireless Data Research Group predicted the market for RFID hardware, software and services would increase at a 23 percent annual growth rate from more than $1 billion in 2003 to $3 billion in 2007.

About 49 percent of IT professionals queried in the April 2004 Survey on RFID Adoption: Current and Future Plans said they had a high level of RFID understanding.

Forty-five percent of those surveyed see RFID as a revolutionary technology that will have widespread impact, which means perhaps the number of IT professionals with a high level of understanding should be closer to 100 percent.

Understanding RFID

RFID systems wirelessly exchange information between a tagged object and a reader/writer, and that information is eventually sent to a host computer. Surprisingly the technology is rather old. During World War II, the British Royal Air Force used RFID devices to distinguish returning British fighter planes from German ones. More than 60 years later, RFID technology has been refined, enhanced and integrated with information technology.

Radio waves transfer data between the RFID tag and the read/write device, which are tuned to the same frequency. The read/write device sends out a signal, which is received by all tags in the radio frequency field and tuned to that specific frequency. The tags' antennas receive the signal, and selected tags respond by transmitting their stored data.

The tag can hold many types of data about the item, such as its serial number, configuration instructions, what time the item traveled through a certain zone, temperature and other data depending on the sensors placed in the tag.

The read/write device receives the tag signal with its antenna, decodes it and transfers the data to the host computer.

Basic Components

The actual RFID tag has two basic elements -- a computer chip and an antenna, which are mounted onto an insert and encapsulated to form either a finished tag or label.

Tags can be as small as a grain of rice, as large as a brick or flat and flexible, and durability ranges depending on tag placement and environmental conditions. They can be used -- and reused -- for a lifetime. "Paper-thin labels, often referred to as 'smart labels,' are typically used for disposable applications, and as such, are not as durable," according to Intermec.

RFID tags are either passive or active. Passive tags don't have their own power supply, are often quite small and have a range of no more than 5 meters. Active RFID tags have their own power source, longer ranges and larger memories than passive tags, and can store additional information.

Antennas emit radio signals to activate tags, and read and write data to them, according to, and come in various shapes and sizes. They can be built into doorframes to receive tag data, or mounted on an interstate tollbooth to monitor traffic passing by on a freeway, the Web site states.

The reader/RF module emits radio waves in ranges from one inch to 100 feet or more, depending on its power output and the radio frequency used, states. The reader decodes the data in the tag's integrated circuit (silicon chip) and the data is passed to the host computer for processing.

RFID Controversy

The primary debate regarding RFID

Jessica Jones  |  Managing Editor