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 CO2 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 CO2 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.

中文翻译：

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用于养鸟业的数据密集型无芯片 RFID 多传感器

这封信展示了具有多参数传感功能的 22 位数据密集型无芯片射频识别 (RFID) 标签。标签半径为 7.4 mm，由双极化入射平面波激发。Kapton® HN 标签装载有作为辐射材料的铜和作为 CO2 传感器的多壁碳纳米管 (MWCNT)。在宽度为 0.2 毫米的金属板内部精细蚀刻槽。标签的频率响应可见于 4–25 GHz 频段。湿度水平的升高会导致 Kapton® HN 基板的电气特性发生变化，这在标签的频率响应中观察到的共振漂移。相比之下，CO2 气体浓度的变化会导致纳米管化学成分的差异，这在最内槽的频率共振中观察到。标签在极端大气条件下表现出可靠的行为并返回其初始状态。所提出的多参数传感器的这种可逆特性使其成为商业环境传感器的经济可靠的替代品。