Radio-Frequency Identification Chips or RFID chips are extensively used today. Some of the many applications of these are supermarket products, dog-tags and even humans to support operations and to keep track of their locations. RFIDs are powered by external signals, are very small, and therefore can simply be hidden out of sight. Unlike barcodes which are passed over a laser scanner, RFIDs operate on radio hence they just need to be in the area to be detected; as a result they are very effective and economical. One of the pioneers in RFID technology, marketing and production is Alien Technology. They made RFID tags, readers and printers that are in compliance with today's standards. The tag detects radio signals and sends back response by means of radio waves. However, a very minimal amount of power is needed to sends back response and therefore would just take a split second to complete the whole process.
Today, RFIDs are employed in all sectors and industries such as in machine-driven payment, counterfeit prevention, smart homes and offices, supply chain management, physical access control, logistics and security, and airline baggage management. In stores and shopping malls, RFID tags are usually attached to the price label or hidden inside of the product or clothing. A thin flat tag is called a “label”, an even thinner and usually made of paper tag is called a “ticket”, while a “card” is the chip inserted in a thin plastic like employee IDs or access cards. On the other hand, “glass bead” is a tough small tag in a cylindrical ball or bead. These tags are very safe to use in tagging animals and tough enough to keep them tagged on. Custom designed RFIDs operate in different frequencies depending on its applications
The development of many applications was due to the accuracy and reliability of RFID devices, such as material tracking, manufacturing process control and confirmation, airline luggage identification, and routing systems and single-pass multiple item identification. All processes were modified through the development of intelligent tracking management. Toll collection and container tracking has significantly become efficient which lead to traffic-free highways and faster identification. The recent application of RFIDs in payment systems is Mobil Speedpass. Although very expensive, Active and Semi-passive RFID tags are usually used for highly valuable items while passive tags are used for low-value goods.
The operations of RFIDs are limited to short distances only. Normally the tags are readable to a maximum of few feet. Generally, Passive RFIDs are used if the area has less interference and the distances are at the range of few inches to a few yards.
RFID System
Bar codes are printed almost in every product that consumers can buy. It is a machine-readable parallel bars that stores binary codes and shows information about the product. With the advancement in technology, bar codes are becoming obsolete. The latest technology called radio frequency identification (RFID) is on its way. Every person has his identity either by his name or by his characteristics and every thing has its identity either by its name or by its quality. Thus in this period where everything is wireless, a specific frequency can become an identity of a person or an object, and this is made possible by RFID technology.
RFID therefore provides identity to an object. A standard RFID system consists of reader, tag and a system that process the data. The reader transmits the RF waves and the tag, on the other hand, receives the signal. The information carried by the RF wave can also be transmitted to the host PC or even to LAN.
RFID technique is becoming a leading technology in terms of electronic data collection and transmission. The system uses radio frequencies or electromagnetic waves in the range of 10-30 KHz (VLF) to 30-300 GHz (UHF).A common application may use 50 KHz-2.5GHz.
The basic RFID system is made up of the following blocks:
RFID TAG
This is the device which is attached to the object or item to be tracked. It consist an electronic chip used to store data, which to be transmitted through RF waves going to the reader. The main function of the tag is to respond from the request transmitted by the reader to access the stored data within it.
Active and passive tags are the two types of RFID tags; the first includes battery while the latter does not. Passive tags are smaller and lighter compared to active tags and has an infinite lifetime. However, they require more power from the reader and have a shorter range of operation.
RF ID READER
This device instructs the RF transceiver to transmit RF signals, receives the encoded signal from the tag through RF transceiver, decodes the tag's information, and transmits the information or identification to the host PC.
THE CONTROL SECTION
The information gathered by the reader from the tag can be relayed to the host PC or LAN. RFID operates in several frequency bands. The standard frequencies for RFID are:
Each of the frequency bands has its own advantages and disadvantages. The lower frequencies 125-134 kHz and 13.56 MHz have a superior operation in areas near water or areas crowded with people.
The maximum possible communication distance between tag and reader is called read range. The performance also depends on the sensitivity of the operating frequency of the receiver and the orientation of the antenna. Read range is not only a function of power output from the reader, but also a function of the power available within the tag, the kind of antenna used, different environmental conditions, and operating frequencies used by the system.
This is the brief idea of RFID and its basics concepts. Widespread applications of RFID are also observed in real time systems such as asset management, item management, automatic vehicle location, animal tagging, electronic toll collection, airport security system, access control and so on.
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