一种共面波导馈电的圆极化天线的设计

Design of a CPW Fed Circularly Polarized Antenna

RFID系统在当今社会应用广泛,天线在RFID系统中的作用尤其重要,圆极化天线的设计大大提高了系统的灵活性和可靠性。给出了一款通用频带的特高频RFID阅读器天线。该天线通过共面波导馈电,在介质层顶部的接地平面刻蚀方形槽,为了增加天线阻抗带宽,将共面波导馈线弯折设计;为了提升天线的圆极化性能,在槽内适当添加L型连接线。该天线实现了410 MHz的阻抗带宽和488 MHz的轴比带宽,天线尺寸为115 mm×115 mm×0.3 mm。

RFID system is widely used in today＇s society. The role of antenna in RFID system is especially important, and the design of circularly polarized antenna greatly improves the flexibility and reliability of the system. A universal frequency band RFID reader antenna is presented in this paper. The antenna is fed by coplanar waveguide, and square groove is etched on the ground plane layer on top of the medium. In order to increase the antenna impedance bandwidth, the CPW （coplanar waveguide） feeder is bent. In order to enhance the performance of circular polarization antenna, the L type connecting line is added to the slot. The antenna achieves 410 MHz impedance bandwidth and 488 MHz axis ratio bandwidth, and the antenna size is 115 mm×115 mm×0.3 mm.