Radio Frequency Identification (RFID)

Radio Frequency Identification is a system that uses radio waves to identify and track objects. The most common type of RFID is small computer chips—sometimes smaller than a grain of rice—that can be embedded in the item. The computer chip contains a transmitting antenna. The chip is called a RFID tag. When a device named a reader sends out radio waves, the tag sends back information it stores. The information within the tag can be modified or replaced. The distance of the radio waves used in RFID is important since it determines how far the tag can be from the reader.

There is also a chipless RFID tag which uses fibers instead of actual computer chips. The fibers would deflect back the radio waves sent by the reader. The pattern of deflected waves depends on the unique arrangement of the fiber, thus enable identification of the object connected with the tag. The advantage of this type of RFID tag is that it is less expensive and can work in various types of setting. The disadvantage is that it cannot hold much data. Some chips even require a clear path toward the reader.

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