What Is Passive RFID?
RFID (an acronym for radio frequency identification) is a technology that uses small tags, some as small as a grain of rice, that can be read by a passive RFID reader. A passive tag doesn't contain a battery; instead, it draws power from a passive reader when the tag is scanned. Information is stored in the tag and picked up by the reader. The term "passive" distinguishes this type of tag from an active tag, which does contain a battery. Passive tags have a wide range of uses, including identifying ownership of cattle and other livestock.
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History
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RFID has been in use since the World War II, but it was not until years later that it was considered cheap enough for widespread commercial use. The technology originated in the work of Léon Theremin, who created a tool for the Soviet Union in 1945 that retransmitted radio waves using sound. His device was used as a secret listening device and was nothing like RFID as we now know it. However, it is regarded as the predecessor to the current technology, although the first passive identification device was produced by Mario Cardullo in 1973.
Advantages
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Because a passive RFID tag does not contain a battery, it has a life of at least 20 years. An active tag has a much shorter shelf life because the battery eventually stops functioning. A passive tag is less expensive to manufacture than an active tag, and the fact that it is so small means it has a much wider range of uses. Some of the possible applications include tracking consumer goods, people and animals, and authenticating passports. The technology is also widely used in transportation and ticketing systems. One of the main disadvantages of a passive tag is that, while an active tag can be read from a distance of 100 feet, a passive tag can only be read from a distance of a few feet at most.
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Applications
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The uses for RFID tags are almost endless. All kinds of merchandise and property from airplanes to farm animals and car parts to passports have passive tags attached or inserted to allow them to be tracked. Passive tags are used as an alternative to supermarket bar codes, and many transportation systems around the world, such as the Moscow metro, use RFID tags in passenger travel cards. Clothes shoppers have undoubtedly encountered passive RFID, which is in the security tag attached to merchandise. This type of tag has been used in libraries for some time.
Controversy
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Technology is inevitably susceptible to abuse and because RFID tags are used for tracking goods and animals, it seems logical that tracking people would be the next step. This is by far the most controversial use of RFID technology. In 2006, the Food and Drug Administration approved the implantation of passive tags in humans, although this does not mean that it is widely used. Some advocate using tags in this way to protect children, so that if they are abducted it is easy to track them.
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References
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