RFID or Radio Frequency Identification, is the new technology talked about for product identification and data storage that can be used where barcodes fail. It is based on the same concept as barcode except that the method of encoding data is different since barcodes require a line of sight optical scan. As an automatic identification technology it reads encoded data with the aid of radio frequency waves. Its biggest advantage is that it does not necessarily need a tag or label to be visible to read the data stored.
RFID tags fall into two categories, active or passive. Active tags have an internal battery with a read and write option, allowing modification of data. The memory size of the tag is variable with some tags having memory space of up to 1 MB. Passive RFID tags do not have an external power source and instead use the power generated from the reader. They are therefore lighter, cheaper, and have an unlimited lifetime of operation, unlike active tags have a ten-year span. Passive RFID tags are programmed with a special set of data that cannot be changed and being read-only, they operate as a license plate in a database.
Passive RFID tags have a low-power integrated circuit attached to an antenna and a protective packaging is used to enclose it depending on the application it is going to be used for. The IC has an on-board memory that stores data. The IC uses the antenna to receive and transmit information to an external reader, generally referred to as an interrogator. Tags are also called inlays and transponders. In technical terms an inlay is simply a tag on a flexible substrate ready for conversion into a smart label. The smart label can extend the basic functioning of RFID by combining barcode technology and human readable information. Smart labels include an adhesive label embedded with an RFID tag inlay. Thus they provide the benefits of read range and the unsupervised capability of tags, with the flexibility and convenience of on-demand label printing.
RFID systems have variable frequency ranges, and the frequency level decides their use for applications. Their biggest asset is their operation without a line-of-sight and without contact. Thus they can be read through fog and snow, heat and dust, and other environmentally tough conditions where barcodes or any other optical identification systems would fail. Their high reading speeds are another advantage even though RFID technology is more expensive.
At present almost every RFID implementation is different due to the performance requirements and cost factors besides the signal transmission restrictions. They are used where barcodes prove inadequate but that does not men that RFID technology will replace barcodes. The market is big enough for both to continue side by side.