Line width limitations of flexographic-screen- and inkjet printed RFID antennas

As RFID tags are now being produced in very large amounts there is a great desire to simplify their construction by printing the antennas using electrically conductive ink. Printed antennas from silver-based inks can provide almost the same efficiency as their corresponding copper antennas and there are several ways to accomplish the printing process. Different printing processes all have their advantages and disadvantages. As silver, when used as a conductive material, is naturally more expensive than copper, this is the reason that it is important to minimize the amount used per antenna. This article presents a study of the limitations in a minimum line width for flexographic-, screen-, and inkjet printed RFID antennas.