Single-Layer, Flexible, and Depolarizing Chipless RFID Tags

This work presents the designs of single-layer chipless radio frequency identification (RFID) tags based on the RF-encoding particles (REP) approach. These tags are the first realized for reading in cross-polarization resulting in a higher immunity against multipath, and thus, achieving robust readings in a practical environment. The proposed chipless tags are of credit-card size, with a frequency band of operation ranging from 3 to 6 GHz within the ultra-wideband (UWB), compliant with low-cost additive fabrication techniques, and realized with low-cost plastic and paper substrates. A study on reader-tag polarization and rotation angle is performed for the proposed designs and compared with the existing designs of two-layers. For the first time, it is presented that the low-cost single-layer tags can be read in realistic environments with only one measurement.