一种超高频射频识别读写器天线

本文提出了一种适用于我国UHF RFID读写器的宽带圆极化叠层微带天线,通过选用廉价FR4板、空气层介质和对角线切角的正方形贴片组成叠层结构,采用S型水平蜿蜒带条激励主辐射贴片的馈电方式,展宽了天线的阻抗带宽和轴比带宽.所提出的S型水平蜿蜒带条馈电技术,实现了对称的辐射方向性图.给出了天线设计思路,并利用电磁仿真软件分...

A UHF RFID Reader/Writer Antenna

A novel broadband circularly polarized stacked patch antenna is proposed for Chinese UHF radio frequency identification (RFID) reader/writer applications.The antenna is composed of two corner truncated patches and an S-shaped horizontally meandered strip (HMS),all of which are printed on the upper side of the FR4 substrates.One end of the S-shaped HMS is connected to the main radiating patch by a probe,while the other end is connected to an SMA connector.Using the proposed S-shaped HMS feed technique,a good impedance matching and symmetrical broadside radiation patterns can be achieved.Simulation results are compared with the measurements,and a good agreement is obtained.The measurements show that the antenna has an impedance bandwidth (VSWR＜1.5) of about 26.6% (722-944MHz),a 3dB axial ratio (AR) bandwidth of about 10.8% (838-934MHz),and a gain level of about 8.5dBi or larger within the 3dB AR bandwidth.Therefore,the proposed antenna can be a good candidate for UHF RFID readers/writers operating between 840 and 928MHz.