This research proposes an integrated high-frequency (HF) and ultrahigh-frequency (UHF) passive radio frequency identification (RFID) tag antenna for near-field (13.56 MHz) and far-field (920–925 MHz) communication. This tag antenna is advantageous for the applications with lossy material in the near-field communication and mitigates polarization loss in the far-field communications. The HF-RFID tag antenna is of square spiral structure, and the circularly polarized UHF-RFID structure consists of a square loop radiator with cascading loop feeding and shorted stub. The structure of HF-RFID tag antenna situated inside the circularly polarized UHF-RFID tag can avoid the significant effect of the near-field magnetic coupling from the square loop. The UHF-RFID tag antenna is realized by using characteristic mode analysis for wideband circular polarization. The HF-RFID structure is conjugate-matched with NXP NT3H2111 chip, and the UHF-RFID structure is conjugate-matched with NXP G2X chip. Simulations were carried out, and an antenna prototype was fabricated. The experimental results reveal that the radiation pattern of UHF-RFID tag antenna is bidirectional with a gain of 0.31 dBic. The impedance bandwidth covers the frequency range of 903–944 MHz, and the axial ratio in boresight direction at 922.5 MHz is 1.67 dB, with the axial ratio bandwidth over 863–938 MHz. The maximum near-field and far-field reading ranges are 4.9 cm and 8.7 m. The proposed integrated dual-band passive tag antenna is operationally ideal for HF-RFID and UHF-RFID applications.

中文翻译：

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近场HF-RFID和基于CMA的圆极化远场UHF-RFID集成标签天线

这项研究提出了一种集成的高频（HF）和超高频（UHF）无源射频识别（RFID）标签天线，用于近场（13.56 MHz）和远场（920-925 MHz）通信。该标签天线对于在近场通信中具有损耗材料的应用是有利的，并且减轻了在远场通信中的极化损耗。HF-RFID标签天线为方形螺旋结构，圆极化UHF-RFID结构由具有级联环路馈电和短截线的方形环路辐射器组成。位于圆极化UHF-RFID标签内部的HF-RFID标签天线的结构可以避免来自方形环路的近场磁耦合的显着影响。UHF-RFID标签天线是通过对宽带圆极化使用特征模式分析来实现的。HF-RFID结构与NXP NT3H2111芯片共轭匹配，UHF-RFID结构与NXP G2X芯片共轭匹配。进行了仿真，并制造了天线原型。实验结果表明，UHF-RFID标签天线的辐射方向图是双向的，增益为0.31 dBic。阻抗带宽覆盖903-944 MHz的频率范围，视轴方向上的轴向比率在922.5 MHz处为1.67 dB，轴向比率带宽在863-938 MHz以上。最大近场和远场读数范围为4.9 cm和8.7 m。拟议中的集成双频无源标签天线在操作上非常适合HF-RFID和UHF-RFID应用。HF-RFID结构与NXP NT3H2111芯片共轭匹配，UHF-RFID结构与NXP G2X芯片共轭匹配。进行了仿真，并制造了天线原型。实验结果表明，UHF-RFID标签天线的辐射方向图是双向的，增益为0.31 dBic。阻抗带宽覆盖903-944 MHz的频率范围，视轴方向上的轴向比在922.5 MHz时为1.67 dB，轴向比带宽在863-938 MHz范围内。最大近场和远场读数范围为4.9 cm和8.7 m。拟议中的集成双频无源标签天线在操作上非常适合HF-RFID和UHF-RFID应用。HF-RFID结构与NXP NT3H2111芯片共轭匹配，UHF-RFID结构与NXP G2X芯片共轭匹配。进行了仿真，并制造了天线原型。实验结果表明，UHF-RFID标签天线的辐射方向图是双向的，增益为0.31 dBic。阻抗带宽覆盖903-944 MHz的频率范围，视轴方向上的轴向比在922.5 MHz时为1.67 dB，轴向比带宽在863-938 MHz范围内。最大近场和远场读数范围为4.9 cm和8.7 m。拟议中的集成双频无源标签天线在操作上非常适合HF-RFID和UHF-RFID应用。并制造出天线原型。实验结果表明，UHF-RFID标签天线的辐射方向图是双向的，增益为0.31 dBic。阻抗带宽覆盖903-944 MHz的频率范围，视轴方向上的轴向比率在922.5 MHz时为1.67 dB，轴向比率带宽在863-938 MHz以上。最大近场和远场读数范围为4.9 cm和8.7 m。拟议中的集成双频无源标签天线在操作上非常适合HF-RFID和UHF-RFID应用。并制造出天线原型。实验结果表明，UHF-RFID标签天线的辐射方向图是双向的，增益为0.31 dBic。阻抗带宽覆盖903-944 MHz的频率范围，视轴方向上的轴向比率在922.5 MHz处为1.67 dB，轴向比率带宽在863-938 MHz以上。最大近场和远场读数范围为4.9 cm和8.7 m。拟议中的集成双频无源标签天线在操作上非常适合HF-RFID和UHF-RFID应用。最大近场和远场读数范围为4.9 cm和8.7 m。拟议中的集成双频无源标签天线在操作上非常适合HF-RFID和UHF-RFID应用。最大近场和远场读数范围为4.9 cm和8.7 m。拟议中的集成双频无源标签天线在操作上非常适合HF-RFID和UHF-RFID应用。