Printed 3-D stacked chipless RFID tag with spectral and polarization encoding capacity

A fully printable 3D stacked chipless RFID tag on a 50-μm thin polyimide film is presented. The tag consists of multi-layer cross-polarized dipole resonators which overlap. The data encoding is performed in the multiresonating circuit which is comprised of multiple stop band resonators. The resonators are printed using screen printing technology using a silver based conductive paste. The chipless RFID tag is designed specifically for security applications which are suitable for mass deployment for low cost items in trillions.