Custom Search

Sunday, September 20, 2009

Radio-frequency identification

Radio-frequency identification

Radio-frequency identification (RFID) is the use of an object (typically referred to as an RFID tag) applied to or incorporated into a product, animal, or person for the purpose of identification and tracking using radio waves. Some tags can be read from several meters away and beyond the line of sight of the reader.

Most RFID tags contain at least two parts. One is an integrated circuit for storing and processing information, modulating and demodulating a radio-frequency (RF) signal, and other specialized functions. The second is an antenna for receiving and transmitting the signal.

There are generally three types of RFID tags: active RFID tags, which contain a battery and can transmit signals autonomously, passive RFID tags, which have no battery and require an external source to provoke signal transmission and battery assisted passive (BAP) which require an external source to wake up but have significant higher forward link capability providing great read range.

Today, RFID is used in enterprise supply chain management to improve the efficiency of inventory tracking and management.

Source : Wikipedia



You Tube videos




RFID chip hand implantation



How to block RFID chips


RFID chips are very similar to barcodes in the sense that a certain amount of data is contained within them, and then transmitted to a reading device which then processes and utilizes the information. The
major difference is that barcodes have to be physically visible to the reading device, which is usually only able to scan them at a distance of a 12 inches or less. RFID tags, on the other hand, do not have to be visible to the reading device. They can be scanned through clothes, wallets, and even cars. The distance from which they can be read is also much greater than that of a barcode. At DEFCON an RFID tag was scanned at a distance of 69 feet, and that was back in 2005, the possible reading distance now is probably much greater than that.

There are a few different categories of RFID tags, but the most common ones, and the ones we will be dealing with in this instructable, are the "passive" type. Passive RFID chips contain no internal power supply. They contain an antenna which is able to have a current induced in it when within range of the RFID reader. The tag then uses that electricity to power the internal chip, which bounces its data back out through the antenna, where it will be picked up by the reader.

No comments:

Post a Comment