RFID In Complex Environments

By Paul Dixon, Emerson & Cuming Microwave Products

Two of the difficulties limiting widespread acceptance of RFID are the tagging of objects with complex electromagnetic properties, and tagging of objects used in extreme environments. Standard RFID tags work very well when applied to cardboard boxes in climate controlled warehouses but in the real world, tags are needed that work well directly on metal or in metallic environments. Tags are also needed that work well in extreme environments characterized by exposure to chemicals, invasive force and/or high temperature.

RFID tagging with the capability to be read on or in close proximity to metal has proven to be one of the most difficult problems in the RFID world. Simple dipoles, which represent a vast majority of the most common RFID antennas due to their ease in manufacturing, are perhaps the worst culprits, performing very poorly near metal surfaces.