UHF频段RFID标签天线的小型化设计

Design for the Miniaturized RFID Tag Antenna in UHF Band

提出了一种UHF频段的小型化标签天线,采用紧凑的弯折偶极子形式,通过附加一种新的T型阻抗匹配环结构,得到了非常好的阻抗匹配效果。针对Alien Higgs2型标签芯片,芯片的阻抗为7.4-j113Ω,天线在915 MHz工作频率下的输入阻抗为7.40Ω+112.98Ω,两者实现了较好的共轭匹配。天线整体平面尺寸为20 mm×60 mm,比常见的弯折偶极子结构标签天线的尺寸缩减了25%。天线的S11<-3 dB的工作频段为884 MHz到958 MHz,覆盖了74%的UHF频段,最大增益为0.94dBi。结果表明该天线具有良好的辐射性能,具有低损耗、小型化的优点。

A miniaturized UHF band tag antenna which is composed of a compact folded dipole is presented. The tag antenna has a T-match loop that brings about a good impedance match. Input impedance of the proposed tag antenna is 7.40＋j112.98Ω,which is conjugate-matched up a Alien Higgs2 IC chip with impedance of 7.4-j113 Ω at 915 MHz. Its total size is 20mm×60mm,which is reduce about 25% of a conventional folded dipole tag antenna. The operating bandwidth（ return loss less than -3 dB ,884 MHz -958 MHz）covers 74% of the entire UHF RFID band. It has a high gain of 0.94dBi. The proposed antenna keeps good radiation performance and has advantages of low cost and small size.