Data-Dense Chipless RFID Multisensor for Aviculture Industry

This letter presents a 22-bit data-dense chipless radio frequency identification (RFID) tag with a multiparameter sensing feature. The tag has a radius of 7.4 mm, and it is excited with dual-polarized incident plane waves. Kapton® HN-based tag is loaded with copper as a radiating material and multiwall carbon nanotubes (MWCNTs) as a CO 2 sensor. The slots are finely etched inside the metal sheet having a width of 0.2 mm. The frequency response of the tag is seen in the 4-25-GHz band. The rise of humidity level yields a change in the electrical properties of the Kapton® HN substrate that is observed in the frequency response of tag in terms of resonance drifting. In contrast, a change in CO 2 gas concentration yields a difference in the chemical composition of nanotubes that are observed in the frequency resonance of the innermost slot. The tag exhibits a reliable behavior in extreme atmospheric conditions and returns to its preliminary state. This reversible nature of the proposed multiparameter sensor makes it an economical and reliable alternative to commercial environmental sensors.