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Electronics and Telecommunications Research Institute (한국전자통신연구원)
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HF RFID Reader Antenna with Loop Switch for Avoiding Magnetic Coupling

  • Choi, Won-Kyu (IT Convergence Technology Research Laboratory, ETRI) ;
  • Jeong, Seung-Hwan (IT Convergence Technology Research Laboratory, ETRI) ;
  • Park, Chan-Won (IT Convergence Technology Research Laboratory, ETRI) ;
  • Pyo, Cheol-Sig (IT Convergence Technology Research Laboratory, ETRI) ;
  • Son, Hae-Won (Division of Electronics and Information Engineering, Chonbuk National University)
  • Received : 2014.02.21
  • Accepted : 2014.10.24
  • Published : 2014.12.01
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Abstract

This paper studies the magnetic coupling between two adjacent loop antennas that are parallel to each other in a plane and presents a new practical method to avoid the resulting magnetic coupling interference. The study focuses on the high frequency radio-frequency identification (RFID) system for casino applications, where several loop antennas are closely built into a game table to monitor gaming chips. In this case, neighboring loop antennas may severely interfere with each other by magnetic coupling, which leads to the malfunction of the RFID system. In this paper, we present a practical loop antenna with a new loop switch circuit for avoiding magnetic coupling. The loop switch circuit is integrated with a matching circuit and automatically operated by using an interrogating signal from a reader. We verified the validity of the proposed design by showing that an RFID reader with the proposed antenna can exactly and separately read the gaming chips placed on the different betting zones of a game table.

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References

  1. X. Qing and Z.N. Chen, "Characteristics of a Metal-Backed Loop Antenna and its Application to a High-Frequency RFID Smart Shelf," IEEE Antennas Propag. Mag., vol. 51, no. 2, Apr. 2009, pp. 26-38.
  2. J.-N. Lee et al., "Design of an Ultra-Compact UHF Passive RFID Tag Antenna for a Medical Sample Tube," ETRI J., vol. 34, no. 6, Dec. 2012, pp. 974-977. https://doi.org/10.4218/etrij.12.0212.0161
  3. J.-H. Cho et al., "HF RFID Reader Antenna Generating Horizontal Magnetic Fields for Casino Applications," IEEE Antennas Propag. Soc. Int. Symp., Orlando, FL, USA, July 7-13, 2013, pp. 1118-1119.
  4. A.S. Abul-Kassem and D.C. Chang, "On Two Parallel Loop Antennas," IEEE Trans. Antennas Propag., vol. 28, no. 4, July 1980, pp. 491-496. https://doi.org/10.1109/TAP.1980.1142370
  5. E.R. Joy, A. Dalal, and P. Kumar, "Accurae Computation of Mutual Inductance of Two Air Core Square Coils with Lateral and Angular Misalignments in a Flat Planar Surface," IEEE Trans. Magn., vol. 50, no. 1, Jan. 2014.
  6. A.P. Sample, D.A. Meyer, and J.R. Smith, "Analysis, Experimental Results, and Range Adaptation of Magnetically Coupled Resonators for Wireless Power Transfer," IEEE Trans. Ind. Electron., vol. 58, no. 2, Feb. 2011, pp. 544-554. https://doi.org/10.1109/TIE.2010.2046002
  7. HFSS, ANSYS Inc., Canonsburg, PA, USA. Accessed Mar. 3, 2013. http://www.ansys.com
  8. CX2147NL, RF Transformer. Accessed June 12, 2013. http://www.pulseelectronics.com
  9. NSR0240HT1G, Schottky Barrier Diode. Accessed June 12, 2013. http://www.onsemi.com
  10. LBZX84CLT1G, Zener Diode. Accessed June 12, 2013. http://www.lrc.cn
  11. 9012-05-10, Electrical Relay. Accessed May 10, 2013. http://www.cotorelay.com
  12. Near Field Probe Set Broadband Response Model EM-6992 Instruction Manual, Electro-Metrics, Inc., Accessed May 10, 2013. http://www.tek.com/sites/tek.com/files/media/media/resources/ EM-6992%20Manual.pdf
  13. Tag Chip of NXP ICODE ILT. Accessed June 3, 2013. http://www.nxp.com/documents/data_sheet/SL2S1402_SL2S150 2_SL2S1602.pdf
  14. ISO/IEC 18000-3 Information Technology, Radio Freq. Identification for Item Manag., Part 3: Parameters for Air Interface Communications at 13.56 MHz, 2010.