【作者】 杨兵；

【导师】 冯全源；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2009， 硕士

【摘要】 射频识别技术(RFID)是目前一种热门的非接触式自动识别技术,它利用无线射频方式进行非接触双向通信,从而达到自动识别目标对象并获取相关数据,与其它识别方式相比,该技术具有识别精度高、速度快、环境适应能力强等许多优点。目前UHF频段和微波频段的RFID技术发展很快,阅读器天线是RFID系统中的关键部分,因此它的研究与设计很重要。本文对微波S频段RFID阅读器天线设计进行了研究,文中首先介绍了RFID的相关知识,并对天线设计的重要性做了简要介绍,然后对微带贴片天线和它应用在RFID阅读器天线设计上的优势进行分析,并在其后采用微带贴片天线来设计阅读器天线。其次本文对使用在便携式或手持式阅读器上的单片微带天线进行了研究,对采用的极化方式,基板材料进行分析,最后设计出一款同轴馈电单片圆极化切角微带贴片天线,仿真结果表明该天线有着优良的性能,天线辐射方向性好,半功率波束宽度大于70°,阻抗带宽在200MHz左右,圆极化轴比带宽在40MHz左右,峰值增益达到7.5dB,且该天线结构简单,易于制造,非常适合于使用单天线的RFID阅读器天线设计。再次本文针对远距离阅读器天线需要高增益要求,对采用天线阵来设计阅读器天线的方式进行研究,并设计了一款四元阵的圆极化贴片天线阵,仿真结果表明,其增益符合理论计算,在13dB左右,阻抗带宽70MHz,圆极化轴比带宽50MHz,半功率波束宽度在25°左右,能够运用在特殊场合(覆盖范围不是很宽,阅读距离远,增益要求却很高)的RFID阅读器天线设计,最后文章对于采用阵列式的阅读器天线在实际设计中碰到的问题进行了简要分析。更多还原

【Abstract】 Radio Frequency Identification (RFID) has been one of the most popular automatically intelligent identification technologies in the recent years, which can identify the target and exchange useful digital information via non-contact radio frequency communication between RFID readers and Tags. Compared with other identification technology, RFID has higher precision, faster identification speed and stronger ability to adapt the un-constant environments. Nowadays, UHF and microwave frequency band RFID technology develops rapidly. RFID reader antenna is a key part of the system, so it’s very important to do some research on them.In this paper, the RFID Reader antenna which works in microwave S-band is analyzed, first, some basic knowledge of RFID is introduced, and the importance of the RFID reader antenna design is simply present. Then the advantages of using micro-strip patch antenna to design RFID antenna are analyzed and researched, for its advantages micro-strip patch antenna is used to design the RFID reader antenna.Second, the single patch antenna which uses in portable or hand-held reader is studied, the form of its polarization and the substrate material is discussed, after that a coaxial feed circular polarization single micro-strip patch antenna is designed for the hand-held reader, simulation results show that this antenna has excellent performance, it has good radiation direction and the half power beam width is greater than 70°, the impedance bandwidth is about 200Mhz and the circular polarization axis ratio bandwidth is about 40Mhz, the gain is around 7.5dB. The antenna’s structure is simple and easy to manufacture, it’s very suitable for single RFID reader antenna.Third, for the high-gain RFID reader antenna is needed more and more, the micro-strip antenna array is introduced to design the high-gain RFID reader antenna. A four circular polarization patch array is present, simulation results show that its performance is good ,the gain is about 13dB,impedance bandwidth is around 70Mhz and the circular polarization axial ratio bandwidth is about 50Mhz, half-power beam width is about 25. This antenna can be used in some special places (narrow coverage, far distance and high-gain requirement places).Finally some problems of using array antenna for RFID reader antenna are discussed in this paper.更多还原