RFID阅读器天线设计与小型化研究

发布时间：2018-05-18 10:57

本文选题：RFID + 阅读器天线　；参考：《南京航空航天大学》2014年硕士论文

【摘要】：射频识别(RFID, Radio Frequency Identification)技术是一种利用射频电磁波获得目标对象数据的非接触式通信技术。目前业界最关注UHF(840-960MHz)频段的RFID技术，也在逐步探索2.45GHz和5.8GHz的RFID产品。而阅读器天线是RFID系统中传递无线电波的部件，对它的研究与设计具有重要意义。首先，本文总结了RFID阅读器天线的相关知识，并针对标签天线摆放位置确定的情况，提出了一款小型化的PIFA型RFID阅读器天线，该天线结构简单，工作频段为835-851MHz,覆盖了我国用于RFID自主研发的840-845MHz频段，，增益峰值为1.6dBi。其次，本文对微带天线圆极化实现方法进行了研究，结合传统的微带天线设计步骤，设计了一款基于DGS结构的圆极化微带贴片天线，采用1.6mm厚的FR4基片。仿真结果显示，该天线阻抗带宽在42MHz左右，圆极化轴比带宽在10MHz左右，在925MHz增益峰值达到0.8dBi，与不加入缺陷地结构的天线相比，该款天线增益提高了3dBi左右。为了进一步提高增益，采用加厚介质基板的方法，最终设计出一款阻抗带宽94MHz，轴比带宽21.3MHz，在920-925MHz的平均峰值增益均大于3.2dBi的圆极化RFID阅读器天线，且该天线结构简单，造价低，很适用于UHF频段的RFID阅读器的设计。最后，本文分析了微带天线多频实现的常用方法，并针对阅读器天线需要多频段的要求，利用缝隙加载的方法设计了一款可工作于920-925MHz和2.4-2.45GHz的双频圆极化RFID阅读器微带天线，仿真结果表明，天线在微波频段的两段阻抗带宽分别是905-954MHz和2.424-2.470GHz，3dB轴比带宽分别是916.6-928.2MHz和2.420-2.451GHz，并在轴比带宽内的平均增益分别是1.6dBi和3.5dBi，适用于双频圆极化RFID阅读器的设计。
[Abstract]:Radio Frequency Identification (RFID) and Radio Frequency Identification) (Radio Frequency Identification) technology is a contactless communication technology which can obtain object data by radio frequency electromagnetic wave. At present, the industry pays most attention to the RFID technology in UHF 840-960MHz band, and is exploring the RFID products of 2.45GHz and 5.8GHz step by step. Reader antenna is the part of transmitting radio wave in RFID system, so it is of great significance to research and design it. Firstly, this paper summarizes the relevant knowledge of RFID reader antenna, and proposes a miniaturized PIFA RFID reader antenna, which has a simple structure. The working frequency range is 835-851 MHz, which covers the 840-845MHz band of RFID developed independently in China. The gain peak value is 1.6 d Bi. Secondly, the realization method of circular polarization of microstrip antenna is studied in this paper. A circular polarization microstrip patch antenna based on DGS structure is designed by combining the traditional design steps of microstrip antenna. The 1.6mm thick FR4 substrate is adopted. The simulation results show that the impedance bandwidth of the antenna is about 42MHz, the ratio bandwidth of circular polarization axis is about 10MHz, and the peak gain of 925MHz is 0.8dBi. compared with the antenna without defective ground structure, the gain of this antenna is increased by about 3dBi. In order to further improve the gain, the method of thickening dielectric substrate is used to design an impedance bandwidth of 94 MHz, and the axial ratio bandwidth of 21.3 MHz. The average peak gain in 920-925MHz is higher than that in 3.2dBi, and the structure of the antenna is simple and the cost is low. Very suitable for UHF band RFID reader design. Finally, this paper analyzes the common methods of multi-frequency realization of microstrip antenna, and designs a dual-frequency circularly polarized RFID reader microstrip antenna which can work in 920-925MHz and 2.4-2.45GHz. The simulation results show that the two-band impedance bandwidth of the antenna in microwave band is 905-954MHz and 2.424-2.470GHz / 3 dB axial ratio bandwidth is 916.6-928.2MHz and 2.420-2.451GHz respectively, and the average gain in the axial ratio bandwidth is 1.6dBi and 3.5dBi. it is suitable for the design of dual-frequency circularly polarized RFID reader.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP391.44;TN822

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