RFID Systems

Radio frequency identification, or RFID, is an incredibly useful concept for many industries. RFID Systems are similar in purpose to a bar code or a photograph for use with video imaging software. RFID Systems use radio waves to communicate with a transceiver, which communicates to a computer, all through the use of antennae. This non-optical transmission allows for identification in a variety of circumstances.

RFID Systems have three main components:

• The RFID tag with its own data, functions and physical characteristics
• The reader (static or portable) with its own functions and physical characteristics
• The host with its own hardware, functions and predefined tasks

Radio frequency identification systems, or RFID Systems, are rapidly providing solutions to a variety of businesses and organizations worldwide. Identification concepts are utilized to monitor or track the subject for different purposes. These RFID Systems can trace people, animals, or any object. Using radio waves, the subject's tag communicates with an antenna, which then relays the information to a central database or computer. This is allowing real-time availability of information, and the capacity to change data, using radio waves.

The benefits of the RFID Systems are tailored precisely for their specific uses. The tags are available in a wide range of sizes and shapes to accommodate any subject. The basic setup involves an antenna, a transceiver equipped with a decoder, and a RF tag, called a transponder. The systems dramatically differ in complexity and cost. For several industries, the numerous benefits conferred by RFID are invaluable.

RFID Systems Are Applicable in Many Industries: Each part of the RFID Systems can vary in complexity and sophistication depending on its intended usage. The type of tag is active or passive, and can vary in the amount of data it contains. Simple RFID Systems might be the ones that a shipping company uses to track boxes. They may choose passive tags that are simple, with small capacities for information, like a sticker. The simplest tag may contain identification numbers, and is activated by the radio waves being emitted by an antenna. When it passes in front of the antenna, its id number will be sent to the antennae, which relays it to a central database. This database can use the results to track and organize the shipments.

A more complex application is exemplified in hospitals and correctional facilities. The most common RFID use is in the form of a wristband. The tag is in the band, and can be programmed with information, like the patient's or inmate's name and identification number. Depending on the intentions of the hospital or prison, the entire system can be more or less complex. Basically, the tags can contain varying types and amounts of information based on their memory capacity, and the radio wave frequency ranges, or distance the tag and antenna can be apart, varies. RFID Systems of all forms are providing indispensable aide to businesses and organizations worldwide.

RFID Systems have gained popularity, and notoriety, in recent years. A driving force behind the rapid development of RFID technology has been the rise of pervasive commerce, sometimes dubbed the quiet revolution. Pervasive commerce uses technologies such as tracking devices and smart labels embedded with transmitting sensors and intelligent readers to convey information about key areas where consumers live and work to data processing systems. To gather this data, retailers can choose from a range of options.

RFID Systems may be roughly grouped into four categories:

• EAS (Electronic Article Surveillance) systems: Generally used in retail stores to sense the presence or absence of an item. Products are tagged and large antenna readers are placed at each exit of the store to detect unauthorized removal of the item.
• Portable Data Capture systems: Characterized by the use of portable RFID readers, this enables this system to be used in variable settings.
• Networked systems: Characterized by fixed position readers which are connected directly to a centralized information management system, while transponders are positioned on people or moveable items.
• Positioning systems: Used for automated location identification of tagged items or vehicles.

These RFID Systems enable business owners to have real-time access to inventory information, as well as a broader, clearer picture of consumers' buying habits. RFID technology also enables retailers and corporations to peek into the lives of consumers in ways that were, until recently, off limits. Products embedded with RFID tags can continuously transmit information ranging from an electronic product code (EPC) identifier, to information about the item itself, such as consumption status or product freshness. Data processing systems read and compile this information and can even link the product information with a specific consumer.

This composite information is vastly superior—and more invasive—than any data that could be obtained from scanning bar codes, or even loyalty cards. Frequent shopper cards link consumers to their purchases, but this limited information gives retailers only a narrow view of consumers' in-store purchasing trends. In contrast, RFID Systems enable tagged objects to speak to electronic readers over the course of a product's lifetime—from production to disposal—providing retailers with an unblinking, voyeuristic view of consumer attitudes and purchase behavior.

There are two main categories for RFID Systems on the market today. These are near field systems that employ inductive coupling of the transponder tag or Smart Label to the reactive energy circulating around the reader antenna, and far field systems that couple to the real power contained in free space propagating electromagnetic plane waves. Near field coupling techniques are generally applied to RFID Systems operating in the LF and HF bands with relatively short reading distances well within the radian sphere defined by λ/2π, while radiative far-field coupling is applicable to potentially longer read range UHF and microwave RFID Systems. This short technical paper is confined to the case of inductively coupled near-field RFID Systems operating in the internationally available 13,56 MHz ISM frequency band.

RFID Systems are also distinguished by their frequency ranges. Low-frequency (30 KHz to 500 KHz) systems have short reading ranges and lower system costs. They are most commonly used in security access, asset tracking, and animal identification applications. High-frequency (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) systems, offering long read ranges (greater than 90 feet) and high reading speeds, are used for such applications as railroad car tracking and automated toll collection. However, the higher performance of high-frequency RFID Systems incurs higher system costs. The significant advantage of all types of RFID Systems is the non contact, non-line-of-sight nature of the technology.