Effects of Conductivity, Thickness, and Width on UHF RFID Tag Antenna Efficiency
Project Award Date: 08-09-2006
An RFID microchip attached to an antenna is embedded between layers of laminated paper or plastic foil, creating inlays or unfinished RFID labels. Traditionally, inlays have been constructed from etched copper or aluminum. Etching is a subtractive process and uses chemicals that are difficult to dispose.
Newer inlays are being created using printed silver-based inks, including those from Symbol and RSI ID. Printing is an additive process, so it has a number of advantages. However, silver suffers from two important drawbacks. First, the conductivity of printable inks are less than that of copper, and thus antennas may be less efficient (especially for tags designed to work near metal). Second, silver is considered a heavy metal and may pose an environmental problem. Those concerns have spurred developments in other additive technologies, such as vapor- deposited aluminum, and electroplated and electro-less copper.
ITTC researchers will measure the performance of antennas with various conductive materials and thicknesses and establish the ideal free-space thickness of copper.
Primary Sponsor(s): MacDermid, Inc.