Rfid

RFID TECHNOLOGY

P.SREEKANTH,

P.SUNDEEP KUMAR

IV/IV, ECE

VNR VJIET

ADRESS FOR CORRESPONDENCE

1) P.SREEKANTH

H.NO.111

REDDY COLONY

CHANDANAGAR

HYD-500050

PH-23035514

E-MAIL SREEKANTHPERUR@YAHOO.CO.IN

2) P.SUNDEEP

PH NO 27206663

EMAIL SUNDEEP_38@YAHOO.COM

RFID TECHNOLOGY

ABSTRACT

In a few years from now the very concept of supply chain management, for that instance any field where object tracking is involved is going to change drastically.

The reason, advent of the so called RFID technology which helps in keeping track of your objects. This does not require any manual intervention to keep track of the object. A small component called RF tag/transponder attached to the object helps in tracking the objects. This technology not only helps in tracking of objects but also helps in various applications such as secure access, theft- detection etc .the basic components of RFID system are RF tag, antenna/reader, and controller. Tags being of active (power supply required) or passive (power supply not required) type. Day by day the applications of this technology are finding their place in many fields like tracking cattle for prevention of mad cow disease and tracing its origin. With the standards appearing and the cost of tags becoming lesser, this technology is set to create a revolution in the automated data capture industry and in common mans life

This paper explains the concept of RFID technology, differences between active and passive tags, its applications, and infirmities

INTRODUCTION

RFID stands for radio frequency identification. RF tags or transponders carry data about the things to which they are attached. RFID technology is based on bidirectional radio frequency communication between a base station and an ID tag or badge attached to the item to be tracked. Data within a tag may provide identification for an item in manufacture, goods in transit, a location, the identity of a vehicle, an animal or individual. By including additional data the prospect is provided for supporting applications through item specific information or instructions immediately available on reading the tag. RFID technology, being used as a substitute for bar code technology doesnÐŽ¦t need restrictions such as line-of-sight, read-only, and clean environment with added advantages such as reduced cost for tracking the item, no manual intervention etc

COMPONENTS OF AN RFID SYSTEM

Components of an RFID system are

1) RFID tags/transponders

2) Antenna/reader

3) Controller

ACTIVE AND PASSIVE RFID TAGS

There are two types of tags Active and Passive RFID tags

Active RFID uses an internal power source (battery) within the tag to continuously power the tag and its RF communication circuitry

Whereas Passive RFID relies on RF energy transferred from the reader to the tag to power the tag.

Passive RFID either 1) reflects energy from the reader or 2) absorbs and temporarily stores a very small amount of energy from the readerÐŽ¦s signal to generate its own quick response. In either case, Passive RFID operation requires very strong signals from the reader, and the signal strength returned from the tag is constrained to very low levels by the limited energy.

On the other hand, Active RFID allows very low-level signals to be received by the tag (because the reader does not need to power the tag), and the tag can generate high-level signals back to the reader, driven from its internal power source. Additionally, the Active RFID tag is continuously powered, whether in the reader field or not. As discussed in the next section, these differences impact communication

range, multi-tag collection capability, ability to add sensors and data logging, and many other functional parameters.

Technical differences between Active and passive RFIDÐŽ¦s

Functional Capabilities of Active and Passive RFID

Because of the technical differences outlined above, the functional capabilities of Active and Passive RFID are very different and must be considered when selecting a technology for a specific application.

i. Communication Range

For Passive RFID, the communication range is limited by two factors: 1) the need for very strong signals to be

received by the tag to power the tag, limiting the reader to tag range,

and 2) the small amount of power available for a tag to respond to the reader, limiting the tag to reader