12-11-2012, 05:48 PM
A Seminar Report ON RFID
rfid.ppt (Size: 2.39 MB / Downloads: 37)
Introduction of RFID:-
Radio frequency identification technology known as RFID , has been described as “tech’s official Next Big Thing”. RFID is not actually a new technology ,but it is being applied in anew way, suprred by technological advance & decreased costs. Once used during world war 2 to identify friendly aircraft, RFID is now being used in a variety of public & private sector setting from hospital to the highway.In pharmacy a druggist can fill a prescription from a bottle bearing an RFID chipped label confirming the authenticity of it’s content. On the high way , cars with RFID tags on their windshield can move a swiftly through high way tool booths , saving time & reducing traffic congestion. RFID is benefits for industry & consumers. RFID is used in supply chain management. RFID used in public sector like a workshop. RFID research is health care where RFID devices can be used to track equipment and people within a medical facility . The most significant concern expressed by consumers familiar with RFID related to privacy.
History of RFID:-
It’s generally said that the history of RFID technology can be traced back to world war 2. The Germans, Japanese, Americans and British were all using radar which had been discovered in 1935 by scottish physicist sir Robert Alexander Watson- watt- to warm of approaching planes. While they were still miles away. RFID is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna—the chip and the antenna together are called an RFID transponder or an RFID tag. The antenna enables the chip to transmit the identification information to a reader. The reader converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can make use of it.
The chip:---
usually made of silicon, contains information about the item to which it is attached. Chips used by retailers and manufacturers to identify consumer goods may contain an Electronic Product Code (“EPC”). The EPC is the RFID equivalent of the familiar universal product code (“UPC”), or bar code, currently imprinted on many products. Bar codes must be optically scanned, and contain only generic product information.
Full-wave antennas:-
The full-wave loop is approximately one wavelength in circumference. Resonance is obtained when the loop is slightly longer than one wavelength. The full-wave loop can be thought of as two end-connected dipoles. Like the half-wave loop, the shape of the full-wave loop is not critical, but efficiency is determined mainly by the enclosed area. The feed impedance is somewhat higher (approximately 120Ω) than the half-wave loop.