What Is an RFID Chip?

by Don Cunningham

Long queues at shopping malls could vanish when Radio Frequency Identification chips replace the pervasive Universal Product Code. Imagine going into a store or mall, filling a cart to the brim and marching right out the exit. You won't need to wait for the teller to scan every purchase in your cart. Instead RFID chips attached to each item send information to a nearby reader that senses the products in the cart and scans each almost instantaneously. The reader is linked to a computer network that conveys information on your purchases to the merchandise manufacturers and retailers. Your bank is alerted and the total of your purchases is debited from your account.

Components of an RFID Chip System

A representative RFID chip system has three components: host computer network, a reader transceiver and tags. An RFID tag, which is affixed to products, is a radio gadget made up of an unsophisticated silicon microchip fixed with an inbuilt antenna; it sends and receives signals from an RFID reader transceiver. The reader broadcasts and accepts radio frequency data to and from the tag by means of antennas. The information obtained by the reader is transmitted to a host computer that uses RFID software to refine the data and dispatch it to the appropriate applications to be converted into meaningful information.

Types of RFID Chip Systems

RFID systems have two inclusive categories: active and passive. Active systems contain their own power source, while passive systems have no power supply and instead respond to an electromagnetic signal from the reader. They can also be grouped based on the frequency band in which they function.

Low-Frequency RFID

The low-frequency band encompasses frequencies ranging from 30 to 300 kilohertz. Most LF RFID systems function at 125 kHz, but some function at 134 kHz. This band facilitates a small read range of about 4 inches and possesses prolonged read speed compared to other higher frequencies. It is not highly sensitive to radio wave interference. LF RFID chips are used in livestock tracking and access control.

High-Frequency RFID

The high-frequency band spans from 3 to 30 megahertz. The majority of HF RFID systems work at 13.56 MHz with read ranges from 4 to 40 inches. This frequency band encounters medium sensitivity to interference. HF RFID chips are used in data transfer applications, ticketing and payments.

Ultra High-Frequency RFID

The ultra high-frequency band encompasses the range from 300 MHz to 3 GHz. A passive UHF network read range can be as broad as 40 feet. The frequency band has the quickest rate of data transfer compared to LF or HF and is the most sensitive to radio wave interference. UHF product makers have devised techniques of developing antennas, readers and tags that maintain performance even in extreme conditions. UHF RFID chips have myriad applications including pharmaceutical anti-counterfeiting, retail inventory management and wireless device configuration.

About the Author

Don Cunningham has been an engineering and technology writer and editor for more than five years. He has served as a technical writer for software and Internet companies and as a writer and editor for tech magazines and the web. He has also experience in IT including mainframes, programming, client/server, networks, project management, security, disaster recovery, information systems and hardware.

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