Abstract

A circularly polarised RFID tag antenna with wide axial ratio bandwidth, wide impedance bandwidth and simple tuning network is presented. The antenna, based on the widely used crossed-dipole design, incorporates a novel matching network based on two large L-shaped strips joining the arms of the dipoles to match the impedance. The L-shaped strips create large area loops enabling the antenna to be adapted to the high inductances required for good matching without the currents flowing through them degrading the axial ratio of the antenna. The gain pattern, input impedance and axial ratio (AR) are computed with numerical simulation and measurements, resulting in a 30 MHz bandwidth based on the −3 dB Axial Ratio criterion, which can provide a maximum reading distance of 12.8 m.

中文翻译：

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宽轴比带宽交叉偶极RFID天线

摘要

提出了一种具有宽轴比带宽，宽阻抗带宽和简单调谐网络的圆极化RFID标签天线。该天线基于广泛使用的交叉偶极子设计，结合了一个新颖的匹配网络，该网络基于两个大的L形带，这些带将偶极子的臂连接起来以匹配阻抗。L形条带产生了大面积的环路，使天线能够适应良好匹配所需的高电感，而不会流过它们的电流降低天线的轴向比率。增益模式，输入阻抗和轴向比（AR）是通过数值模拟和测量计算得出的，基于-3 dB轴向比标准，可提供30 MHz的带宽，最大读取距离为12.8 m。