金属磁性对超高频RFID标签增益的影响  

Effect of metal magnetism on UHF RFID tag gain

作　　者：李柏杨 韩冬桂 刘芳 李达 燕怒 LI Baiyang;HAN Donggui;LIU Fang;LI Da;YAN Nu(School of Mechanical Engineering and Automation,Wuhan Textile University,Wuhan 430000,China)

机构地区：[1]武汉纺织大学机械工程与自动化学院,湖北武汉430000

出　　处：《现代电子技术》2020年第22期23-26,共4页Modern Electronics Technique

基　　金：湖北省教育厅优秀中青年科技创新团队计划项目(T201607);国家自然科学基金面上项目资助(51775388)。

摘　　要：金属介质尤其是磁性金属对UHF射频信号存在干扰,严重影响了超高频射频识别(UHF RFID)技术的有效应用。该文采用电磁仿真软件Ansoft Maxwell分析不同金属内电磁损耗的差异,并运用Ansoft HFSS软件研究了超高频RFID标签天线在磁性金属与非磁性金属表面工作的特性。结果显示磁性材料金属内电磁损耗远大于非磁性金属,表现为对电磁波的吸收作用。金属磁性对标签天线辐射方向性影响不明显,但对天线增益抑制作用较为严重,并随着磁导率损耗正切tanμ从0增大到0.5,磁性金属表面天线的增益从2.41 dB衰减到1.72 dB。基于理论分析及仿真分析结果,该文提出一种将陶瓷基板与添加环形微带线相结合的天线结构设计方法增大辐射阻抗,提高天线增益,从而减小金属磁性对天线工作性能的影响。The metal media,especially magnetic metals,interferes with UHF RF signals,which seriously affects the effective application of ultra high frequency radio frequency identification(UHF RFID)technology.In this paper,the electromagnetic simulation software Ansoft Maxwell is used to analyze the difference of electromagnetic loss in different metals,and the Ansoft HFSS software is used to research the performance of UHF RFID tag antenna working on magnetic metal and nonmagnetic metal surfaces.The results show that the electromagnetic loss in the metal of the magnetic material is much larger than that of the non-magnetic metal,which is manifested as the absorption of electromagnetic waves.The metal magnetism has no obvious effect on radiation directivity of tag antenna,but it has a serious effect on antenna gain suppression.As the increase of magnetic permeability loss tangent tanμfrom 0 to 0.5,the gain of magnetic metal surface antenna decreases from 2.41 dB to1.72 dB.Based on the theoretical analysis and simulation analysis results,an antenna structure design method combing the ceramic substrate with the added circular microstrip line is proposed to increase the radiation impedance and improve the antenna gain,so as to reduce the influence of metal magnetism on the working performance of the antenna.

关 键 词：金属磁性 超高射频识别 天线增益 电磁损耗分析 天线设计 辐射阻抗匹配 

分 类 号：TN123.34-34[电子电信—物理电子学] TP391.4[自动化与计算机技术—计算机应用技术]