A Flexible Chipless RFID Tag with Polymer Coatings Used for Harsh Environments

This paper proposes a flexible chipless RFID tag with polymer coatings. The tag consists of five resonant rings and a 50-Ω microstrip feeding line, which can realize the 4-bit encoding function in a compact size. Meanwhile, to cope with environmental challenges, the radiant element of the tag is coated with unique protective films made from the Polydimethylsiloxane (PDMS), which can greatly reduce the impact of complex environments with humidity, acid-akali, biofouling, external scratches, and electromagnetic interference. In addition, the integrated tags can be printed on a flexible Rogers Ro3003 substrate, which is insensitive to the variation of ambient temperature and can be more easily attached to curvilinear structural surfaces. Simulation results demonstrate the excellent performance of the proposed tag.