How Do RFIDs Work?
A typical RFID system consists of a scanner and RFID tags. The scanner is essentially a transceiver, which sends out a signal at a specific frequency. This radio, or electromagnetic frequency, creates a scanning zone. When the RFID tag, which is a microchip transponder attached to an antenna, enters the zone, it is powered by the electromagnetic field (for passive RFIDs) and sends back the information it holds.
There are four frequency ranges that RFIDs typically use: high (2.4–2.6GHz), UHF (850–900MHz), high (12–14MHz) and low (125/134.5KHz). The type of frequency used depends on the application. Lower frequencies have less range and are typically used for applications such as the pet chip. Higher frequencies have a greater range but require more power. They are typically used in applications such as tracking shipping containers.