RFID Labels

An RFID label or tag is basically an RFID (radio frequency identification) transponder that is embedded with an IC (integrated circuit) and an antenna. The IC is encrypted with a unique electronic product code (EPC) that is equivalent to an electronic lineage, setting apart the tagged item from any other in the world. When a tag goes comes within the range of an RFID reader, proprietary information is passed on through an antenna to the reader, which then feeds the data to a central computer for processing.

There are two types of RFID labels, namely inductively coupled RFID tags, and capacitively coupled RFID tags. Inductively coupled RFID tags have been used for years to track cows, railroad cars, airline luggage, and freeway tolls. There are three parts of a usual inductively coupled RFID tag, namely silicon microprocessor, metal coil, and encapsulating material. Silicon microprocessor chips differ in size, depending on their purpose. Metal coil is made of copper or aluminum wire, wound into a circular pattern on a transponder, and it acts as a tag’s antenna. The tag sends out signals to a reader, with read distance decided by the size of the coil antenna, and these coil antennas can operate at 13.56 MHz. Encapsulating material is glass or some polymer material that wraps around the chip and coil.

Inductive RFID tags are powered by the magnetic field produced by a reader. The tag’s antenna picks up magnetic energy, and the tag interacts with the reader. The tag then adjusts the magnetic field for retrieving and transmitting data back to the reader, and the reader directs that data to the host computer.

Capacitively coupled RFID tags have been manufactured in order to reduce the cost of radio-tag systems. These tags get rid of metal coil and utilize a little quantity of silicon to accomplish the same function as that of an inductively coupled tag.

A capacitively coupled tag also has three components, namely silicon microprocessor, conductive carbon ink, and paper. As far as silicon microprocessor is concerned, Motorola’s BiStatix RFID tags utilize a silicon chip that is only 3 millimeter square in area. A capacitively coupled tag can store 96 bits of information that would allow for billions of distinct numbers, and these numbers can be assigned to goods. Conductive carbon ink is a special ink that acts as the tag’s antenna. This ink is applied to the paper substrate by using usual printing techniques. A silicon chip is affixed to printed carbon-ink electrodes on the back of a paper label, to create an inexpensive, disposable tag that can be integrated on conventional product labels.