一种RFID小型圆极化四臂螺旋天线

设计了一种用于UHF频段射频识别系统的小型右手圆极化四臂螺旋天线。天线由印制在微带介质板的4个长条形臂组成,通过微带功分器馈电。天线在进行4个端口的单独匹配和功分器相连时,需采用一种新的匹配方法。通过仿真优化,天线尺寸为60 mm×60 mm×6 mm,峰值增益为3.8 dB,带内轴比＜3 dB,3 dB波束宽度＞120°,前后比＞15 dB。实物测试结果与仿真结果吻合。

A Small Circular Polarization Four-arm Spiral RFID Antenna

A compact quadrifilar spiral antenna （QSA） with right-hand circular polarization for UHF band RFID reader is presented. The proposed QSA consists of four long arms printed on substrate and fed by microstrip feed network. A new match method is used when four individual ports are connected to the feed network. The pro- posed antenna has a size of 60 mm× 60 mm ×6 mm, the peak gain is 3.5 dB with the axial ratio under 2 dB, the 3 dB beamwidth is more than 120° and the front-to-back ratio is more than 15 dB. The antenna is fabricated and meas- ured, and the results agree well with the simulation.