Radio Frequency Identification

Submitted By wz1988220
Words: 1196
Pages: 5

Almost all products we buy from supermarkets have a bar code printed on. These bar codes are machine readable parallel bars that reveal information about the products But the days of barcode are numbered. Because the new technology called radio frequency identification (RFID) is getting popular.
One person gets his identity either his characteristics or by his name, one subject gets its own identity either by its quality or by its name. So in this wireless era, a specified frequency can become an identity of a person or an object. This way is possible by using RFID, this wireless technology.
Industry experts forecast that more than 1 billion RFID tags will be used in apparel stores in 2011, up from approximately 70 million tags in 2009 — a phenomenally explosive growth rate.
RFID (Radio Frequency Identification), is a subcategory of Automatic Identification and Data Collection (AIDC) technologies. RFID technology is concerning electronic data collection and transmission. The system uses radio frequencies that is, electromagnetic waves in the range 10-30 KHz(VLF) to 30-300 GHz(UHF). Through different radio frequencies, RFID can provide any object to identify.

During World War II, military used RFID as a means to distinguish the air crafts that belonged to them from the enemy air crafts. Since then, RFID has left its military history far behind, and became a sophisticated technology which has the potential to change our lives and works for better.
Over the decades, research in RFID continued to advance. By the 1980s and 1990s, advances in RFID, especially used in tracking made the technique more popular and companies began to consider how RFID would help them to monitor products in real time as they go in entire supply chain.

TAG: A tag is the device, which is attached with the item, which is to be tracked or loaded. The tag consists of electronic chip used to store data that can be broadcast via RF waves to the reader. The main function of the tag is to respond to a transmitted request from the reader for the data stored within the tag.
There are two types of tags, active tags powered by an embedded battery in and Passive ones without battery” would be appropriate. So because the passive tag get power by radio wave and has no battery in, it has infinite life, and at the same time is smaller and lighter than active ones with lower cost. On the other hand, More power which drives reader working is provided by reader so that their radio frequency range is very narrow.
READER: The reader directs the RF transceiver to transmit RF signals, receives the encoded signal from the tag through the RF transceiver, decodes the tag's identification, and transmits the identification with any other data from the tag to the host computer.
THE CONTROL SECTION: this section takes charge in transmitting the information obtained by readers from tags to the host computer.

How Does RFID Technology Work?
RFID tag can be embedded in a product with an integrated circuit chip with specific memory. The memory can store information about the product and at the same time a transponder mechanism can help transmit this information over a radio carrier wave after encoding and modulating it.
Here is how a typical RFID tag reading occurs.
Step 1: Sending Signal
An RFID tagged product may either be passed through a reader or scanner or brought into the vicinity of one. Line of sight identification is not necessary in case of RFID technology and the tags are embedded inside a product. The tag reading process begins with the RFID antenna sending a scanning signal which activates the transponder in a tag to respond. The scanning frequency is chosen to match with the transmitting frequency of the transponder.
Step 2: RFID Tag Transmits Signal
As soon as the active or passive RFID transponder receives the scanning signal, it sends out its own encoded and modulated signal over a radio carrier wave.