DOI QR코드

DOI QR Code

Development of the EM Wave Absorber for Preventing RFID Reader Interference in UHF band

UHF대역 RFID 리더 간섭방지용 전파흡수체 개발

  • Park, Soo-Hoon (Graduate school of Korea Maritime University) ;
  • Choi, Chang-Mook (Graduate school of Korea Maritime University) ;
  • Song, Young-Man (Graduate school of Korea Maritime University) ;
  • Kim, Dong-Il (Department of Radio Science and Engineering, Korea Maritime University) ;
  • Jung, Ji-Won (Department of Radio Science and Engineering, Korea Maritime University) ;
  • Kim, Ki-Man (Department of Radio Science and Engineering, Korea Maritime University)
  • Published : 2008.06.30

Abstract

In this paper, the EM wave absorber was designed and fabricated for preventing Reader Interference of RFID communication system in UHF band We fabricated several samples in different composition ratios of Amorphous and CPE(Chlorinated Polyethylene). Absorption abilities were simulated in accordance with different thicknesses of the prepared absorbers and changed complex relative permittivity and permeability due to composition ratio. The mixing ratio of Amorphous and CPE was searched as 80 : 20 wt.% by experiments and simulation. Then the EM wave absorber was fabricated and tested using the simulated data. As a result, the developed EM wave absorber has a thickness of 4 mm and absorption ability was over 20 dB in frequency range of $860\;MHz{\sim}960\;MHz$. Therefore, it was confirmed that the developed absorber can be used for suppressing RFID reader interference in UHF band.

본 논문에서는 UHF대역 RFID 통신 시스템 간에 발생하는 리더 간섭을 방지하기 위한 전파흡수체를 설계 및 제작하였다. 먼저 자성손실 재료인 Amorphous와 지지재인 CPE(Chlorinated Polyethylene)를 이용하여 조성비별 전파흡수체 샘플을 제작하였고, 이 전파흡수체 샘플로부터 구한 재료정수를 이용하여 시뮬레이션을 한 결과, 최적의 조성비가 Amorphous : CPE = 80 : 20 wt.% 임을 확인하였다. 그리고 시뮬레이션 결과를 토대로 전파흡수체를 실제작하여 전파흡수능을 비교 분석하였다. 그 결과 Amorphous : CPE = 80 : 20 wt.%의 조성비 일 때, 두께 4 mm의 전파흡수체가 $860\;MHz{\sim}960\;MHz$의 주파수 범위에서 전파흡수능 20 dB 이상의 특성을 얻음으로써 UHF대역의 RFID 리더 간섭을 억제할 수 있음을 확인하였다.

Keywords

References

  1. 김동일(2006), "전파흡수체 공학", 대영사, pp. 176-203
  2. 이윤덕, 김도윤, 윤현구, 육종관, 장병준(2007), "리더 간섭에 의한 RFID 시스템의 인식 거리 감소에 관한 연구", 한국전자파학회전자파기술지, 제18권 제7호, pp. 63-69 https://doi.org/10.5515/KJKIEES.2007.18.7.731
  3. Choi, C. M., Kim, D. I,. Choi, D. H., and Li, R.(2006), "Development of Broad-Band Electromagnetic Wave Absorber for X-band Sensors in Double-layered Type Using Carbon", 12th IAIN World Congress, vol. 1, pp. 297-300
  4. Engels, D. W. and Sarma, S. E.(2002), "The reader collision problem", IEEE International Conference on Systems, Man and Cybernetics, vol. 3, pp. 92-97
  5. Hashimoto, O.(1997), "Introduction to Wave Absorber", Tokyo:Morikita Shuppan, pp. 79-81
  6. Kwon, H. J., Shon, H. J. and Hur, W. D.(1995), "The Microwave Absorbing Characteristics of Ferrite Grid Absorber", Journal of Korea Magnetics Society, vol 5
  7. Leong, K. S., Ng, M. L., R. Grasso, A., and Cole, P. H.(2006), "Synchronization of RFID readers for dense RFID reader environments", International Symposium on Applications and Internet Workshop(SAINT' 06), pp. 48-51
  8. Naito, Y.(1987), "Electromagnetic Wave Absorbers", Tokyo:New Ohm, pp. 69-76
  9. Snoek, J. L.(1948), "Dispersion and Absorption in Magnetic Ferrite at Frequency above one Mc/s", Physica, vol. 14, pp. 207-217 https://doi.org/10.1016/0031-8914(48)90038-X