提出了一种宽带标签天线,该天线适用于多标准超高频射频识别(RFID)系统,由一个类偶极子辐射体和一个电感耦合馈电环构成.类偶极子辐射体包含两个变型弯折偶极子天线.这两个变型弯折偶极子天线的长度有差别,可以形成两个相近的谐振点,使得天线的阻抗(特别是虚部)在840~956MHz的范围内保持平稳,以获得与芯片阻抗在较宽频段内的良好的共轭阻抗匹配,从而使天线获得一个非常宽的带宽(816~988 MHz),该带宽足以覆盖全球超高频RFID频率范围,使得标签可以全球通用,大大减少了重复设计工作量,有效降低了成本.最后基于仿真模型,加工了一个天线实物,实物测量结果与仿真结果吻合良好.
Proposed in this paper is a broadband antenna for the application to multi-standard UHF RFID(Radio Frequency Identification) tag,which is composed of a dipole-like radiating body and a inductively-coupled feeding loop.The radiating body consists of two modified meandered dipole antennas different in length so as to form two resonance points only slightly different in frequency.Thus,the antenna impedance,especially its imaginary part,keeps steady in the frequency range of 840 to 956 MHz,and good conjugate impedance matching to the RFID tag chip is obtained.The bandwidth of the antenna varies from 816 to 988 MHz,which is wide enough to cover the global ultrahigh-frequency RFID frequency range,so that the tags with the proposed antenna can be used globally without replicate design and the cost is greatly reduced.Finally,an antenna prototype is fabricated based on the simulation model,with good accordance being found between the simulated and the measured results.