一种新型UHF RFID阅读器圆极化天线

传统的圆极化阅读器天线采用单馈电微带天线方式设计,频带窄、极化特性较差。在单馈电微带天线的基础上,采用探针馈电曲线贴片的方式,在圆形铁片上开了4个对称的方形缝隙,最终设计出一种新型的UHF RFID圆极化阅读器天线。天线的结构尺寸为167.5 mm×167.5 mm×3 mm,阻抗带宽为870~936 MHz,3 dB轴比带宽为900~918 MHz,最大增益为3.5 dB。与传统的圆极化阅读器天线相比,设计的天线频带宽,且极化特性得到良好改善,能够满足工程上的应用需求。

A Novel UHF RFID Reader Antenna with Circular Polarization

Traditional circularly polarized reader antennas using the way of single feed microstrip antenna have characteristics of narrow band and poor polarization. A circularly polarized antenna applied to UHF RFID reader was designed on the basis of single feed microstrip antenna. Probe-fed curve patch feeding methods was used, and four symmetrical square slits were carved on the round plate. The size of the antenna was 167.5 mm×167.5 mm×3 mm. The impedance bandwidth was 870-936 MHz. The 3 dB axial ratio bandwidth was 902-917.5 MHz. The maximum gain was 3.5 dB. Compared with the traditional circularly polarized antenna, the proposed antenna featured a wider bandwidth and an improved polarization characteristics. It met the requirements for the application of engineering.