Composites Research

The Korean Society for Composite Materials (한국복합재료학회)
권호 표지
DOI QR코드

DOI QR Code

Study on Design and Performance of Microwave Absorbers of Carbon Nanotube Composite Laminates

탄소나노튜브 복합재 적층판을 활용한 전파흡수체의 설계 및 성능에 대한 연구

  • 김진봉 (한국기계연구원 부설 재료연구소 복합재료그룹) ;
  • 김천곤 (한국과학기술원 기계공학과 항공우주공학)
  • Published : 2011.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, we present an optimization method for the single Dallenbach-layer type microwave absorbers composed of E-glass fabric/epoxy composite laminates. The composite prepreg containing carbon nanotubes (CNT) was used to control the electrical property of the composites laminates. The design technology using the genetic algorithm was used to get the optimal thicknesses of the laminates and the filler contents at various center frequencies, for which the numerical model of the complex permittivity of the composite laminate was incorporated. In the optimal design results, the content of CNT increased in proportion to the center frequency, but, on the contrary, the thickness of the microwave absorbers decreased. The permittivity and reflection loss are measured using vector network analyzer and 7 mm coaxial airline. The influence of the mismatches in between measurement and prediction of the thickness and the complex permittivity caused the shift of the center frequency, blunting of the peak at the center frequency and the reduction of the absorbing bandwidth.

본 논문에서는 유리섬유 강화 복합재 적층판으로 이루어진 단일층 Dallenbach layer의 전파흡수체의 최적화 기법을 제시하고 그 성능을 분석하였다. 복합재 적층판의 전기적 특성을 제어하기 위해서 탄소나노튜브(CNT)를 혼합한 프리프레그를 사용하였다. 최적화 설계 기법은 유전자 알고리즘을 사용하였으며, 이를 이용하여 다양한 주파수에서 흡수체를 설계하고, 복합재의 두께 및 CNT 함유율을 최적화하였다. CNT 함유율의 최적화를 위해서는 복합재의 복소 유전율의 수치적 모델이 사용되었다. 전파흡수체의 최적설계에서 주파수에 따라서 CNT 함유율은 비례하여 증가하고, 흡수체의 두께는 반비례하여 감소한다. 흡수체의 -10 dB 흡수대역폭은 흡수체가 설계된 중심주파수에 비례하여 증가한다. 설계된 흡수체의 검증을 위해서 10 GHz에서 중심주파수를 갖는 흡수제를 제조하고 그 성능을 평가하였다. 복합재 적층판의 복소 유전율과 전파흡수체의 반사손실은 벡터회로망분석기와 7 mm 동축관을 이용하여 측정하였다. 복합재의 두께와 복소 유전율에 있어서의 측정된 값과 예측치의 차이에 의해서 중심주파수의 이동, 중심주파수에서의 반사손실의 감쇄, 흡수대역폭의 감소가 발생하였다.

Keywords

References

  1. R.A. Stonier, "Stealth aircraft & technology from World War II to the Gulf, Part I: History and Background," SAMPE Journal, Vol. 27, No. 4, 1991, pp. 9-17.
  2. R.A. Stonier, "Stealth aircraft & technology from World War II to the Gulf, Part II: Applications and Design," SAMPE Journal, Vol. 27, No. 5, 1991, pp. 9-18.
  3. M. Bryanton, et al., "Stealth technology for wind turbines," BERR Report No. TES101865, 2007, UK.
  4. K.J. Vinoy, R.M. Jha, "Radar Absorbing Materials from Theory to Design and Characteristics," Boston/Dordrecht/London: Kruwer Academic Publishers, 1996.
  5. E.F. Knott, J.F. Shaeffer, M.T. Tuley, "Radar Cross Section Its Prediction, Measurement and Reduction," Artech House, Inc., 1985, USA.
  6. W. Dallenbach, W. Kleinsteuber, "Reflection and absorption of decimeter waves by plane dielectric layers," Hochfrequenztech und Elektroakust, Vol. 51, 1938, pp. 152-156.
  7. J.H. Oh, K.S. Oh, C.G. Kim, C.S. Hong, "Design of radar absorbing structures using glass/epoxy composite containing carbon black in X-band frequency ranges," Composites: Part B, Vol. 35, 2004, pp. 49-56. https://doi.org/10.1016/j.compositesb.2003.08.011
  8. W.K Jung., B.K. Kim, M.S. Won, S.H. Ahn, "Fabrication of radar absorbing structure (RAS) using GFR-nano composite and spring-back compensation of hybrid composite RAS shells," Composite Structures, Vol. 75, 2006, pp. 571-576. https://doi.org/10.1016/j.compstruct.2006.04.077
  9. S.E. Lee, J.H.Kang, C.G. Kim, "Fabrication and design of multi-layered radar absorbing structures of MWNT-filled glass/epoxy plain-weave composites," Composite Structures, Vol. 76, 2006, pp. 397-405. https://doi.org/10.1016/j.compstruct.2005.11.036
  10. K.Y. Park, S.E. Lee, C.G. Kim, J.H. Hahn, "Fabrication and electromagnetic characteristics of electromagnetic wave absorbing sandwich structures," Composites Science and Technology, Vol. 66, 2006, pp. 576-584. https://doi.org/10.1016/j.compscitech.2005.05.034
  11. W.S. Chin, D.G. Lee, "Development of the composite RAS (radar absorbing structure) for the X-band frequency range," Composite Structures, Vol. 77, 2007, pp. 457-465. https://doi.org/10.1016/j.compstruct.2005.07.021
  12. J.B. Kim, S.K. Lee, C.G. Kim, "Comparison study on the effect of carbon nano materials for single-layer microwave absorbers in X-band," Composites Science and Technology, Vol. 68, 2008, pp. 2909-2916. https://doi.org/10.1016/j.compscitech.2007.10.035
  13. X. Feng, G. Liao, J. Du, L.. Dong, K. Jin, X. Jian, "Electrical conductivity and microwave absorbing properties of nickel-coated multiwalled carbon nanotubes/poly(phthalazinone ether sulfone ketone)s composites," Polymer Engineering & Science, Vol. 48, 2008, pp. 1007-1014. https://doi.org/10.1002/pen.21028
  14. S.E. Lee, O.Y. Choi, H.T. Hahn, "Microwave properties of graphite nanoplatelet/epoxy composites," Journal of Applied Physics, Vol. 104, 2008, pp. 033705. https://doi.org/10.1063/1.2965195
  15. D. Micheli, C. Apollo, R. Pastore, M. Marchetti, "X-Band microwave characterization of carbon-based nanocomposite material, absorption capability comparison and RAS design simulation," Composites Science and Technology, Vol. 70, 2010, pp. 400-409. https://doi.org/10.1016/j.compscitech.2009.11.015
  16. I.M.D. Rosa, A. Dinescu, F. Sarasini, M.S. Sarto, A. Tamburrano, "Effect of short carbon fibers and MWCNTs on microwave absorbing properties of polyester composites containing nickel-coated carbon fibers," Composites Science and Technology, Vol. 70, 2010, pp. 102-109. https://doi.org/10.1016/j.compscitech.2009.09.011
  17. J.B. Kim, C.G. Kim, "Study on the semi-empirical model for the complex permittivity of carbon nanocomposite laminates in microwave frequency band," Composites Science and Technology, Vol. 70, 2010, pp. 1748-1754. https://doi.org/10.1016/j.compscitech.2010.07.006
  18. J. Baker-Javis, et al., "Transmission/reflection and short-circuit line methods for measuring permittivity and permeability," NIST Technical Note 1355-R, 1993.
  19. D.E. Goldberg, "Genetic Algorithm in Search, Optimization, and Machine Learning," Addison-Wesley Publishing Company, Inc., 1989, USA.

Cited by

  1. Electromagnetic interference shielding characteristics for orientation angle and number of plies of carbon fiber reinforced plastic vol.15, pp.4, 2014, https://doi.org/10.5714/CL.2014.15.4.268