UHF 대역 수동형 RFID 태그 쇼트키 다이오드 특성 분석 및 전압체배기 설계

Characterization of Schottky Diodes and Design of Voltage Multiplier for UHF-band Passive RFID Transponder

  • 이종욱 (경희대학교 전자정보대학) ;
  • 트란난 (경희대학교 전자정보대학)
  • Lee, Jong-Wook (School of Electronics and Information, Kyung Hee University) ;
  • Tran, Nham (School of Electronics and Information, Kyung Hee University)
  • 발행 : 2007.07.25

초록

본 논문에서는 UHF 대역 수동 RFID 태그(UHF-band passive RFID tag) 칩 제작에 필수적인 요소인 쇼트키(Schottky) 다이오드를 CMOS 공정으로 제작하고 크기에 따른 특성을 분석하였으며 이를 이용하여 전압체배기를 설계하였다. 쇼트키 다이오드는 Titanium-Silicon 접합을 이용하여 제작되었으며, $4{\times}10{\times}10\;{\mu}m^{2}$의 면적을 가지는 쇼트키 다이오드는 $20\;{\mu}A$의 전류 구동에 대해 약 0.15 V의 순방향 전압 강하의 우수한 특성을 나타내었다. 역방향 파괴전압(breakdown)은 약 -9 V로 수동 RFID 태그칩의 전압체배기에 사용될 수 있는 충분한 값을 나타내었다. 제작된 쇼트키 다이오드의 소신호 등가모델을 이용하여 다이오드의 크기에 따른 순방향 전압강하와 입력 임피던스간의 trade-off에 대해 분석하였다. 이를 이용하여 제작된 6-단 전압체배기는 900 MHz 주파수, 200mV 최대 입력 전압에 대해 1.3 V이상의 출력 전압 특성을 나타내어 인식거리가 비교적 큰 수동형 태그에 적합한 특성을 나타내었다.

In this paper, we present the design of Schottky diodes and voltage multiplier for UHF-band passive RFID applications. The Schottky diodes were fabricated using Titanium (Ti/Al/Ta/Al)-Silicon (n-type) junction in $0.35\;{\mu}m$ CMOS process. The Schottky diode having $4{\times}10{\times}10\;{\mu}m^{2}$ contact area showed a turn-on voltage of about 150 mV for the forward diode current of $20\;{\mu}A$. The breakdown voltage is about -9 V, which provides sufficient peak inverse voltage necessary for the voltage multiplier in the RFID tag chip. The effect of the size of Schottky diode on the turn-on voltage and the input impedance at 900 MHz was investigated using small-signal equivalent model. Also, the effect or qualify factor of the diode on the input voltage to the tag chip is examined, which indicates that high qualify factor Schottky diode is desirable to minimize loss. The fabricated voltage multiplier resulted in a output voltage of more than 1.3 V for the input RF signal of 200mV, which is suitable for long-range RFID applications.

키워드

참고문헌

  1. EPCglobal, 'EPC radio-frequency identity protocols Class-1 Generation-2 UHF RFID air interface Ver. 1.0.9', 2005
  2. 표철식, 채종석, 김창주, 'RFID 시스템 기술', 한국 전자파학회지 전자파기술, 제15권 2호, 2004년 4월
  3. U. Karthaus and M. Fischer, 'Fully integrated passive UHF RFID tansponder IC with 16.7-uW minimum RF input power', IEEE J. Solid-State. Circuits, Vol. 38, pp. 1602-1608, Oct. 2003 https://doi.org/10.1109/JSSC.2003.817249
  4. R. Glidden, C. Bockorick, S. Cooper, C. Diorio, and M. Thomas, 'Design of ultra-low-cost UHF RFID tags for supply chain applications,' IEEE Communication Magazine, Aug. 2004, pp.140-151
  5. K. V. S. Rao, P. V. Nikitin, and S. F. Lam, 'Antenna design for UHF RFID tags: a review and a practical application,' IEEE Tran. Antennas and Propagation, vol. 53, no. 12, Dec. 2005
  6. S. Sankaran and K. O. Kenneth, 'Schottky Barrier Diodes for Millimeter Wave Detection in a Foundry CMOS Process,' IEEE Electron Dev. Lett., vol. 26, no. 7, 2005
  7. G. D. Vita and G. Iannaccone, 'Design criteria for the RF section of UHF and microwave passive RFID transponders', IEEE Tran. Microwave Theory and Tech., Vo. 53, no. 9, Sept. pp. 2978-2990, 2005 https://doi.org/10.1109/TMTT.2005.854229
  8. J.-P. Curty, N. Joehl, C. Dehollain, and M. J. Declercq, 'Remotely powered addressable UHF RFID integrated system,' IEEE J. Solid-State Circuits, vol. 40, no. 11, pp. 2193-2202, Nov. 2005 https://doi.org/10.1109/JSSC.2005.857352
  9. J.-W. Lee, H. Kwon, and B. Lee, 'Design Consideration of UHF RFID Tag for Increased Reading Range,' IEEE MTT-S International Microwave Symposium, 2006, pp. 1588-1591
  10. M. C. A. M. Koolen, J. A. M. Geelen, and M. P. J. G. Versleijen, 'An improved de-embedding technique for on-wafer high-frequency characterization,' in Proc. IEEE Bipolar/ BiCMOS Circuits and Technology Meeting, Sep. 1991, pp. 188-191
  11. J. F. Dickson, 'On-chip high-voltage generation in MNOS integrated circuits using an improved voltage multiplier technique,' IEEE J. Solid-State Circuits, Vol. 11, no. 3, Jun 1976, pp.374-378 https://doi.org/10.1109/JSSC.1976.1050739
  12. F. Kocer and M. P. Flynn, 'A new transponder architecture with on-chip ADC for long-range telemetry applications,' IEEE J. Solid-State Circuits, vol. 41, no. 5, pp. 1142-1148, May 2006 https://doi.org/10.1109/JSSC.2006.872741
  13. E. Bergeret, J. Gabert, P. Pannier, and P. Rizzo, 'Power generation system for UHF passive RFID,' Electron Lett, Dec. 2006, vol. 42. no. 25
  14. J.-P. Curty, N. Joehl, F. Krummenacher, C. Dehollain, and M. J. Declercq, 'A model for-power rectifier analysis and design,' IEEE Trans. Circuits Syst.-I, vol. 52, no. 12, pp.2771-2779, Dec. 2005 https://doi.org/10.1109/TCSI.2005.854294
  15. T. Umeda, H.Yoshida, S. Sekine, Y. Fujita, T. Suzuki, and S. Otaka, 'A 950-MHz rectifier circuit for sensor network tags with 10-m distance,' IEEE J. Solid-State Circuits, vol. 41, no. 1, pp. 35-41, Jan. 2006 https://doi.org/10.1109/JSSC.2005.858620