유도 결합 구조를 응용한 UHF 대역 Near-Isotropic 태그 안테나

Near-Isotropic Tag Antenna in UHF band Using Inductively Coupled Feeding

  • Ahn, Jun-Oh (Department of Radio Engineering, Kyunghee University) ;
  • Jang, Hyung-Min (Department of Radio Engineering, Kyunghee University) ;
  • Moon, Hyo-Sang (Department of Radio Engineering, Kyunghee University) ;
  • Lee, Bom-Son (Department of Radio Engineering, Kyunghee University)
  • 발행 : 2006.12.31

초록

본 논문에서는 유도 결합 구조를 응용하여 등방향 방사 특성에 근접하고 기 상용화된 태그 칩과의 임피던스 매칭과 제작이 용이한 UHF(911 MHz) 대역 RFID 태그 안테나를 설계 제작하였다. 제안된 안테나는 $40{\times}46mm\;(0.12{\times}0.14{\lambda})$의 크기를 가지고 수직 입사의 경우에 최대 RCS가 $-18.5dBm^2$이며, 3 dB RCS 대역폭이 9 MHz(1%)이다. 태그 칩과 안테나 임피던스가 단락 상태일 때의 RCS가 방향에 따라 최대 $-16.9dBm^2$, 최소 $-21.4dBm^2$로 4.5 dB의 차이를 보여, 기존 다이폴 형태의 안테나가 가지는 입사파의 방향에 따른 문제점을 대폭 개선하였다. 또한 설계된 안테나를 제작하여 입사파 각도에 따른 RCS를 측정하였고, 시뮬레이션 결과와 유사함을 확인하였다.

This paper presents an UHF band(911 MHz) RFID tag antenna which has near-isotropic radiation pattern and easy conjugate impedance matching characteristics to any commercial chips of usual practice through the application of an inductively-coupled feeding. The proposed antenna of compact size $40{\times}46mm\;(0.12{\times}0.14{\lambda})$ has, at normal incidence, the maximum RCS of $-18.5dBm^2$ and the 3 dB RCS bandwidth of 9 MHz(1 %) in case of short chip load. It has the maximum and minimum RCS' of $-16.9dBm^2\;and\;-21.4dBm^2$ depending on the incident angles. The difference of about 4.5 dB is relatively small compared with that (about 70 dB) of a pure dipole antenna. The designed antenna has been fabricated and its RCS' have been measured varying the angles of incidence. The measured RCS' have been found to have good agreement with the simulated ones.

키워드

참고문헌

  1. Klaus Finkenzeller, RFID Handbook, John Wiley & Sons, Second Edition, 1999
  2. X. Qing, N. Yang, 'A folded dipole antenna for RFID', IEEE Int. Symp. on AP-S., vol. 1, pp. 97-100, Jun. 2004
  3. K. V. S. Rao, Pavel V. Nikitin, and Sander F. Lam, 'Impedance matching concepts in RFID transponder design', Automatic Identification Advanced Technologies, IEEE, pp. 39-42, Oct. 2005
  4. Hongil Kwon, Bomson Lee, 'Meander line RFID tag at UHF band evaluated with radar cross sections', IEEE. AMPC., vol. 4, Dec. 2005
  5. Namhoon Kim, Hongil Kwon, Jong-Wook Lee, and Bomson Lee, 'Performance analysis of RFID tag antenna at UHF (911 MHz) band', Antennas and Propagation Society International Symposium IEEE, pp. 3275-3278, Jul. 2006
  6. C. Cho, H. Choo, and I. Park, 'Broadband RFID tag antenna with quisi-isotropic radiation pattern', Electron. Lett., vol. 41, pp. 1091-1092, Sep. 2005 https://doi.org/10.1049/el:20052337
  7. Robert E. Collin, Antennas and Radio Wave Propagation, McGraw-Hill Book Company, 1985
  8. John D. Kraus, Ronald J. Marhefka, Antennas For All Applications, McGraw-Hill, Third Edition, 2003
  9. Wonkyu Choi, H. W. Son, Chansoo Shin, Ji-Hoon Bae, and Gilyoung Choi, 'RFID tag antenna with a meandered dipole and inductively coupled feed', Antennas and Propagation Society International Symposium IEEE, pp. 619-622, Jul. 2006
  10. K. Penttila, M. Keskilammi, L. Sydanheimo, and M. Kivikoski, 'Radar cross-section analysis for passive RFID systems', IEE proc.-Microw. Antennas, vol. 153, no. 1, Feb. 2006
  11. Hongil Kwon, B. Lee, 'Evaluation of RFID tag antenna performance using radar cross sections', Wireless Technology, The European Conference, pp. 491-493, Oct. 2005