具有匹配反馈环的微波段RFID标签天线设计

Design of antenna with matching feed loop for microwave 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散射理论，设计和分析了一种具有匹配反馈环的微波段RFID标签天线。谐振频率为2.45 GHz和2.41 GHz天线的尺寸为54 mm×33 mm左右，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300 MHz。可以通过调整匹配反馈环的长度来调整天线的谐振频率，天线的增益为2.4-2.7 dBi。谐振频率为5.8 GHz的天线阻抗带宽为7%，增益为2.8-3.2 dBi，尺寸大小为20 mm×12 mm。通过仿真和测量可知，这种天线能较好地满足RFID微波段标签的要求。

Aimed at the importance of tag antennas in RFID systems,a sort of tag antenna with matching feed loop is designed and analyzed in RFID microwave bands based on the theory of micro-strip antenna design and electromagnetic radiation.The dimension of the antenna operating at 2.45 GHz or 2.41 GHz is around 54 mm×33 mm.The antenna shows near linear phase characteristics,around 300 MHz bandwidths under the condition of Voltage Standing Wave Rration（VSWR） less than 2.The resonant frequency of the antenna can be adjusted by tuning the length of the matching feed loop.The gain of the proposed antenna is 2.4~2.7 dBi.The 5.8 GHz one has bandwidth of 7%（VSWR≤2） and gain of 2.8~3.2 dBi,while the size is just 20 mm×12 mm.Simulation and measurement show that this kind of antennas is suitable for RFID application for all different RFID microwave band tags.