RFID Passive

What is passive RFID?

RFID, or radio-frequency identification, involves the use of a “tag” for the purposes of identification, authentication, or tracking. The tag can store information on an integrated circuit, convert this to a radio-frequency (RF) signal, and transmit or receive these RF signals to an RF reader.The distance at which the tag can be read depends on a number of factors, including the strength of the signal, and the size of the antennae on the tag and the reader.RFID tags can be active or passive. RFID active tags are typically larger and more expensive, but are capable of transmitting signals with the need for an external prompt. RFID passive tags are cheaper, have no battery, but remain dormant until prompted to transmit a signal by an external source.Here we will be focusing mainly on RFID passive tags, which are becoming more common in daily use due to their lower cost.

RFID passive tags

RFID passive tags need to be activated by a reader in order to access the information stored on them.The distance from which a tag can be read depends on a number of factors, including the size of the tag antenna and the amount of power it can draw from the tag reader. Modern RFID tags can be miniaturized to a great degree, the better to be easily embedded in other objects. However, the smaller the tag’s antenna, the lower its range, so the smallest tags can only be read at a very short distance. Various RFID passive tag types are suitable for different applications.

RFID passive applications

As the cost of mass-producing modern RFID passive tags becomes progressively cheaper, use of them has become increasingly common. Inventory systems, road tolls, logistics, animal tracking are just some of the current applications of RFID passive tags. In recent years, a number of countries have started including tags in passports.In other articles, we will look in more detail at some of the current and possible future uses of RFID passive tags.

RFID issues and concerns

Unlike other systems such as the barcode, no single international standard governing RFID is in place. Many countries have their own protocols for governing the allocation of RFID frequencies. As a result, tags of certain frequencies cannot be used worldwide due to conflicting with other uses of these frequencies in certain countries. Security of tags is a major concern. While tag data can be encrypted, this is problematic due to the limited resources available on the tag itself. There is concern that unencrypted tags can be read, possible from a greater distance than originally intended, by a reader which provides additional power to the tag. Many people worry about privacy issues raised by RFID passive tags. These might be used to track stock from manufacture through to point of sale. However, if they remain attached to the product after sale and remain functional, they may be activated at a future date. The security issues mentioned above also have a number of privacy implications. Again, we will look at some of these concerns and what can be done to address them in other articles

Further Reading