What is RFID?

September 26, 2005

Hospitals and pharmacies will be adding radio frequency identification (RFID) tags in the years ahead to curb drug counterfeiting. What is RFID? According to the Association for Automatic Identification and Mobility (AIM), a basic radio frequency identification, or RFID, system consists of three components: an antenna or coil, a transceiver (with decoder), and a transponder, which is also called an RF tag and is electronically programmed with unique information.

Hospitals and pharmacies will be adding radio frequency identification (RFID) tags in the years ahead to curb drug counterfeiting. What is RFID? According to the Association for Automatic Identification and Mobility (AIM), a basic radio frequency identification, or RFID, system consists of three components: an antenna or coil, a transceiver (with decoder), and a transponder, which is also called an RF tag and is electronically programmed with unique information.

The antenna emits radio signals to activate the tag and read and write data to it. Antennas are also conduits between the tag and the transceiver, which controls the system's data acquisition and communication. The antenna can be packaged with the transceiver and decoder to become a reader, which can be configured either as a handheld or a fixed device. The reader emits radio waves in ranges of anywhere from one inch to 100 feet or more, depending upon its power output and the radio frequency used. When an RFID tag passes through the electromagnetic zone, it detects the reader's activation signal. The reader decodes the data encoded in the tag's integrated circuit (a silicon chip), and the data are passed to the host computer for processing

RFID tags come in a wide variety of shapes and sizes and are categorized as either active or passive. Active RFID tags are powered by an internal battery and are typically read/write, which means they can be rewritten and modified. Passive RFID tags operate without a separate external power source and obtain operating power generated from the reader. They are therefore lighter than active tags, less expensive, and offer a virtually unlimited operational lifetime, but they also have shorter read ranges than active tags and require a higher-powered reader. Read-only tags, such as those inserted in drug packages to maintain pedigrees, are typically passive and are programmed with a unique set of data that cannot be modified.

More information about RFID is available at the AIM Web site at http://www.aimglobal.org/.

The author is a writer based in Gettysburg, Pa.