Radio Frequency Identification (RFID)
How does an RFID system work?
A basic RFID solution is comprised of a minimum of three components – a radio frequency tag, which is actually a microchip that is an electronically programmed transponder containing unique information, an antenna device and a transceiver to communicate and decode the stored information.
When the transceiver sends out its electromagnetic waves, they form a magnetic field which "excites" the antenna on the RFID tag. A passive RFID tag accepts the magnetic field and powers the microchip’s circuits. The chip then modulates the waves that the tag sends back to the reader and the reader converts the new waves into digital data.
The recent activity within the RFID industry will definitely improve the cost of components, but for the benefit of this discussion we need some baseline understanding. Passive paper tags, probably the least expensive tag in use, may be available for less than 20 cents, and hardened active tags on reusable containers are available for approximately $20. Transceivers are roughly $1,000 each.
There are several spectrum bands associated with RFID use (see Table below). Spectrum for RFID technology has not yet achieved harmonized international regulations, so use of specific spectrum bands associated with RFID is still a regulatory issue for each administration. Lacking a single standard, organizations could receive product tags for various spectrum bands requiring a transceiver in each of those bands to capture the tag data. In a normal operating environment, the result can be many tags and a number of frequency compatible transceivers.
Since RFID is based on proximity, unlike bar codes and their line-of-sight associated readers, the transceiver can process and analyze all of the "packages" as an entire pallet transits a loading dock. The time savings by not requiring visual contact with the tag are significant.
Tag Types: Passive, Active, Semi-passive
