UHF RFID密集标签互耦效应的频移特性研究

Study of frequency shift characteristics of mutual coupling between UHF RFID tags in dense environment

针对UHF RFID密集环境下标签性能受互耦效应影响的问题,从天线阻抗频移特性的角度对标签间互耦效应进行研究。首先基于电感耦合型标签天线的结构和电路模型,分析带有弯折辐射体结构的标签天线互相耦合时阻抗的频率特性,并通过仿真计算验证了天线阻抗向低频偏移的结论。进一步结合理论和仿真数据分析互耦效应的频率特性,得出天线阻抗的频率偏移导致目标标签的功率传输系数也相应地向低频偏移的结论,从而导致标签的读取性能不稳定。结论对密集标签的性能研究具有指导意义。

Readability of UHF RFID tags in dense environment will be influenced by mutual coupling effect between tags .The paper study mutual coupling effect from the perspective of frequency shift characteristic of antenna impedance . First , based on the structure and circuit model of inductive coupling tag antenna , the frequency characteristic of tag antenna impedance with meander‐line is analyzed ,in consideration of mutual coupling .Then the simulation and calculation verify the conclusion that antenna impedance shifts to lower frequencies .Combined with theory and simulation data ,frequency characteristics of the mutual coupling effect is analyzed .It is put forward that the power transmission coefficient also shifts to lower frequencies , resulting in unreliable reading performance . The conclusion has guiding significance for research on the performance of the dense tags .