几何形状与压实对无线射频识别(RFID)标签印刷天线性能的影响

Geometric and Compaction Dependence of Printed Polymerbased RFID TagAntenna Performance

采用印刷天线的无线射频识别(RFID)标签,成本低,但性能不如金属天线标签。在不增加成本的情况下,提高印刷天线的性能则可替代金属天线。阻抗越低印刷天线的性能越高,而阻抗又取决于天线的厚度和导电油墨的阻抗。为了研究油墨紧度和粗细对阻抗的影响,制备了不同线径的印刷天线。实验结果显示,通过压实印刷天线线圈,阻抗降低40%以上,而电感和电容则维持不变,且印刷天线经压实的RFID标签识别距离明显增加。此外,测试了试制的印刷天线RFID标签,结果表明识别范围已经可以与铜质天线媲美,且发现RFID标签的信号读取范围不依赖于标签的几何形状。稳定读取范围的存在使低精度印刷天线技术的应用成为可能,从而可降低标签制作成本。

Radio frequency identification （RFID） tags with printed antennas are lower in cost but have lower performance than those with metal antennas. Printed antennas can replace metal ones if the performance is increased without raising cost. The performance of printed antennas can be increased if the series resistance in the antennas is lowered. The resistance is dependent on the line thickness and the resistivity of the conductive ink. Printed antennas with different line thicknesses were fabricated to investigate the effect of compaction and thickness on the resistance. The resistance of the printed antenna coils decreased by more than 40% after compaction, while the inductance and the parasitic capacitance were unchanged. RFIDs with compacted printed antennas were found to have significantly increased read range. RFIDs with thick printed antennas were fabricated and tested. These RFIDs were shown to have read ranges comparable to the RFIDs with copper wire antennas. Moreover, a geometry-independent plateau for the read range was found. The presence of a plateau is valuable for thick-line printed antenna since the plateau will enable the usage of low precision printing techniques to lower tag fabrication cost.