具有感应反馈环的超高频RFID标签天线设计

Design of antenna with coupling feed loop for UHF band RFID tags

针对标签天线在RFID系统中的重要性,基于微带天线设计和电磁场散射理论,设计和分析了一种具有感应反馈环的超高频段RFID标签天线。天线的谐振频率为915 MHz,尺寸为78 mm×23 mm,天线显示近线性相位特性,在电压驻波比小于2的条件下,天线的阻抗带宽为100 MHz。可以通过调整感应反馈环的长度来调整天线的谐振频率,天线的增益为2.5 dBi左右。通过仿真和测量可知,这种天线能较好地满足RFID超高频段标签的要求。

Aimed at the importance of tag antennas in RFID systems,a sort of tag antenna with coupling feed loop is designed and analyzed in UHF RFID bands based on the theory of micro-strip antenna design and electromagnetic radiation.The dimension of the antenna operating at 915 MHz is around 78 mm×23 mm.The antenna shows near linear phase characteristics,around 100 MHz bandwidths under the condition of Voltage Standing Wave Ration（VSWR）less than 2.The resonant frequency of the antenna can be adjusted by tuning the length of the coupling feed loop.The gain of the proposed antenna is about 2.5 dBi.By simulation and measurement,it is known that this kind of antennas is suitable for RFID application for all different UHF RFID band tags.