Real-World Implementation Challenges of a Novel Dual-Polarized Compact Printable Chipless RFID Tag

A novel compact printable dual-polarized (DP) chipless radio-frequency identification (RFID) tag is presented along with its real-world implementation challenges. First, the DP tag with simulation and measurement results is presented, where `U´ shaped slot resonators are re-used in both vertical (V) and horizontal (H) polarizations to double the encoding capacity within a fixed bandwidth. Next, slot-length variation encoding technique is added to reduce the tag size by 50%. After that, a 16-bit proof of concept DP tag is developed that achieved 16.6 bits/cm² data density, which is the highest among the reported works. Next, a step-by-step guideline is presented to overcome the real-world challenges for implementing printable chipless RFID tags, which starts with a detail study on the effect of ink conductivity, and permittivity and loss tangent of the substrate on the tag performance. Then, a quick approximate substrate characterization technique is presented, which is verified by measurement of thermal printed patch tags. Finally, tag printing procedure on paper using a thermal printer is briefed, which is followed by a discussion on some printing inaccuracies and their plausible solutions. All these analysis will build a firm understanding and practical insight on implementing the proposed promising conductive ink printed chipless RFID tag for identification, authentication and sensing.