超高频和微波波段RFID标签天线研究

发布时间：2018-03-29 11:02

本文选题：UHF　切入点：2.45GHz　出处：《西安电子科技大学》2014年硕士论文

【摘要】：射频识别即RFID技术,又称电子标签、无线射频识别,是一种通信技术,可通过无线电讯号识别特定目标并读写相关数据,而无需识别系统与特定目标之间建立机械或光学接触。射频识别技术已在全球范围内广泛应用到商业自动化、工业自动化、交通运输管理等众多领域。作为射频识别系统重要的组成部分,射频识别标签的研究日益受到人们重视。而低频和高频射频识别标签的发展相对成熟,在无源射频识别标签的研究中,人们主要集中在超高频和微波波段的研究。因此,研究能够覆盖全球频带所需的超高频和微波波段标签天线,能够为射频识别技术的全球推广和更加广泛的应用提供重要保证。故本文选择超高频和微波波段标签天线设计这一课题进行研究。本文的目的是设计一款小型化2.45GHz标签天线和一款超宽带UHF标签天线,这两款天线都能覆盖全球所需频带范围。其中,2.45GHz全球所需带宽为2.4GHz-2.484GHz;UHF全球所需带宽为840MHz-960MHz。为了实现小型化,2.45GHz标签天线由两个辐射单元构成,其中一个辐射单元是由1阶Hilbert分形结构和弯折偶极子组成,另一个辐射单元仅由弯折偶极子构成。两部分辐射单元相互作用,有效拓展了带宽,可覆盖2.37GHz-2.52GHz近150MHz带宽。同时由于Hilbert分形结构的使用,整个天线的尺寸大大减小,最终小型化尺寸仅为30mm×7.3mm。在整个工作频带内天线的增益可达到2dB,实现了宽频带、小型化、高增益的标签天线。UHF标签天线的设计中借鉴了2.45GHz天线设计的结构特点,其采用1阶Hilbert分形结构和螺旋结构这两个枝节,产生两个接近的谐振点,共同作用拓宽了带宽。同时采用T-匹配网络,通过改变其各枝节的长度和宽度,更方便地调节天线的输入阻抗。最终该天线可覆盖820MHz-1.01GHz超过190MHz的带宽。同时,其增益也超过了2dB,在宽频带的同时也保证了有效辐射。本文还介绍了标签天线性能参数的测量方法,重点说明了双端口测量其带宽的方法,该方法比较简单实用。本人利用该方法测量了上述两款天线的带宽,与仿真结果基本一致,证明了该方法测量天线带宽的准确度和实用性。
[Abstract]:Radio frequency identification (RFID), also known as electronic tag (RFID), is a kind of communication technology, which can identify a specific target and read and write related data by radio signal. There is no need to establish mechanical or optical contact between the identification system and a particular target. RFID technology has been widely used in commercial and industrial automation worldwide. As an important part of RFID system, people pay more and more attention to the research of RFID tags, and the development of low frequency and high frequency RFID tags is relatively mature. In the research of passive RFID tags, people mainly focus on the UHF and microwave bands. Therefore, the UHF and microwave band tag antennas needed to cover the global frequency band are studied. It can provide an important guarantee for the global popularization and wider application of radio frequency identification technology. Therefore, this paper studies the design of UHF and microwave band tag antennas. The purpose of this paper is to design a miniaturized antenna. 2.45GHz tag antenna and an ultra-wideband UHF tag antenna, Both antennas can cover the required global bandwidth, of which the 2.45GHz global bandwidth is 2.4GHz-2.484GHz and the UHF bandwidth is 840MHz-960MHz.To miniaturize the 2.45GHz tag antenna, it consists of two radiation units. One of the radiation units is composed of a first-order Hilbert fractal structure and a bending dipole, while the other is only a curved dipole. The two parts interact with each other, effectively extending the bandwidth. It can cover 2.37GHz-2.52GHz near 150MHz bandwidth. At the same time, because of the use of Hilbert fractal structure, the size of the whole antenna is greatly reduced, and the final miniaturization size is only 30mm 脳 7.3 mm. the gain of the antenna in the whole operating band can reach 2 dB, which realizes wide band and miniaturization. In the design of high gain tag antenna .UHF-tagged antenna, the structural characteristics of 2.45GHz antenna design are used for reference. The first order Hilbert fractal structure and helical structure are adopted to produce two close resonance points. The joint action broadens the bandwidth. By changing the length and width of each branch of the T- matching network, the input impedance of the antenna can be adjusted more conveniently. Finally, the antenna can cover the bandwidth of the 820MHz-1.01GHz over the 190MHz. At the same time, The gain is more than 2 dB, and the effective radiation is also guaranteed in the wide band. This paper also introduces the measurement method of the performance parameters of the tag antenna, with emphasis on the method of measuring the bandwidth of the two ports. The method is simple and practical. The method is used to measure the bandwidth of the two antennas, which is consistent with the simulation results, and proves the accuracy and practicability of the method.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP391.44;TN822

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