A Dual Circularly Polarized RFID Reader Antenna With Wideband Isolation

作者：Lai, Xiao-Zheng^*; Xie, Ze-Ming; Xie, Qi-Qiu; Cen, Xuan-Liang

来源：IEEE Antennas and Wireless Propagation Letters, 2013, 12: 1630-1633.

DOI：10.1109/LAWP.2013.2294173

• Branch-line coupler (BLC)
• circular polarization
• isolation
• radio frequency identification (RFID)
• reader antenna

This letter presents a dual circularly polarized microstrip antenna with wideband isolation for radio frequency identification (RFID) reader application. The proposed antenna consists of a radiating patch and ground plane with a branch-line coupler (BLC) fed by separate Tx/Rx ports. The BLC is located underneath ground and can provide dual circularly polarized radiation coupled to the radiating patch through H-shaped slots. The prototype antenna was fabricated and shows S-11 <= -18 dB and axial ratio AR <= 2 dB from 860 to 940 MHz. The -25-dB isolation characteristic between Tx and Rx ports achieves wide bandwidth of 65 MHz (864-929 MHz), which covers both Europe (865-869 MHz) and USA (902-928 MHz) RFID bands.

• 出版日期2013
• 单位华南理工大学