射頻識別偶極標籤天線於背面有金屬時特性之研究

Research on RFID dipole tag antenna backed by a metal

黃韋翔(Wei-Hsiang Huang)

指導教授 ： 張知難

大同大學/電機資訊學院/通訊工程研究所/碩士(2010年)

摘要

在這篇論文中，我們以915MHz 的RFID 標籤天線進行分析，此天線基本上為一偶極天線架構。此外，在本論文中各種形式的天線架構皆於其背面貼附金屬背板。以最基本的架構來看，此偶極天線被建立在一個有接地的單層FR4 基板上，從研究中我們發現，偶極天線的天線寬度在有效地控制輸入阻抗上扮演著重要的角色，並透過實驗確定了當天線寬度在7.3 公分時會與RFID 晶片阻抗10-j68 歐姆達成共軛匹配。 RFID 讀取距離的實驗在大同大學無反射室中進行，所使用的RFID 讀取器(ALIEN 公司製造型號ALR-9800-TAI)有兩隻天線，每隻天線增益皆為5.9dBi，一隻是用來傳送信號，另一隻則是用來接收RFID 背散射信號。可靠讀取距離的測量是以RFID 標籤至少一分鐘讀取不間斷來決定，在天線寬度7.3 公分時我們得到的讀取距離約為五公尺。為了進一步提高讀取距離，我們在另一個大型金屬背板和前面提到的單層天線結構之間插入保麗龍，透過實驗我們得到當保利龍為2 公分時其讀取距離可增加至5.4 公尺。

關鍵字

射頻識別偶極標籤天線

並列摘要

In this thesis, the 915MHz RFID tag antenna is analyzed. The antenna is basically a dipole. However, it is backed by a metal in various forms. In the simplest form, the dipole is built on a grounded single-layer FR4 substrate. It is investigated that the width of the dipole plays an important role to effectively control its input impedance. To be complex conjugated match with 10-j68 ohm chip impedance, width of the dipole is experimentally determined to be 7.3cm.
Reader range test was conducted in a chamber. A reader unit(model ALR-9800-TAI manufactured by ALIEN Technology) is used. There are two antennas in the unit. Each one has a gain of 5.9dBi. One is for transmitting and the other is for receiving the RFID back-scattered signal. The reliable reader range is judged by the tag being continuously read for at least one minute. Reader range is around 5m in this example. To further increase the reader range, a Styrofoam is inserted between another large metal plate and the aforementioned single-layer structure. It is investigated that reader range can be increased to 5.4m using a 2cm thickness Styrofoam.

並列關鍵字

RFID dipole tag antenna backed by a metal

參考文獻

[1] R. Want, “An Introduction to RFID Technology,” IEEE Pervasive Computing, vol. 5, no. 1, pp. 25-33, Jan. 2006.

[3] C. Turcu, Development and Implementation of RFID Technology. IN-TECH, pp. 13-46, Jan. 2009.

[4] S. L. Chen and K. H. Lin, “A Y-Y-shaped Slot Antenna Design for an RFID Tag Designed for Metallic Tag Applications,” PIERS Proceedings, Aug. 2009.

[5] G. Marrocco, “The art of UHF RFID antenna design: Impedance-matching and size-reduction techniques,” IEEE Antennas and Propag. Magazine, vol. 50, no. 1, pp. 66-79, Feb. 2008.

[6] S. Jeon, Y. Yu, and J. Choi, “Dual-band slot-coupled dipole antenna for 900MHz and 2.45 GHz RFID tag application,” Electron. Lett., vol. 42, no. 22, pp. 1259-1260, 2006.