3D-Printed Fractal UHF RFID Tag Antenna

Fractal geometries are characterized by their unique property of having a not integer dimension, which is often used to determine the filling capacity of a fractal pattern. In antenna design, this peculiarity can be exploited to reduce the size of linear antennas, thanks to a greater electrical length associated with fractal patterns instead of linear ones. In this paper, those properties are further enhanced using 3D printing to realize a small in size, three-dimensional dipole antenna based on the well-known Koch curve fractal pattern, for UHF RFID applications in ETSI band. A commercial composite filament by PREPERM™, suitable to be used with Fused Filament Fabrication technology, has been adopted to realize the dielectric part of the antenna, while an adhesive copper tape has been opportunely shaped to realize the antenna conductive parts. Finally, an Impinj Monza R6 has been mounted as Internal Chip of the prototype. The resulting tag exhibits very good performance, with an estimated maximum reading distance of about 6 meters at 866 MHz, while maintaining a really small footprint of less than 28 mm2.