Complex Dielectric Constant Measurements for Conductor-Loaded Composite Materials Using Genetic Algorithms

유전알고리듬을 이용한 도체 입자가 함유된 복합물질의 복수유전율 측정

  • 이상일 (목포대학교 정보공학부 초고주파공학 연구실)
  • Published : 2005.02.28

Abstract

In this paper, a simple but fast and reliable technique for the complex dielectric constant measurement of non-magnetic materials is introduced using a measured transmission coefficient (S21) and a genetic algorithm as an inversion process at microwave frequencies. In this experiment, it has been found that the transmission method is less susceptible with the measurement errors than that of the reflection method and the genetic algorithm can be efficiently used as a search technique. The suggested technique is validated with known and unknown conductor-loaded lossy materials and the conductor-loaded PCB at X-band.

본 논문에서는 전송방식과 유전알고리듬을 이용하여 간단하지만 빠르고 신뢰성 있는 복수유전율 측정 기법을 제안한다. 측정된 S-파라메터 중 전파계수만을 이용하여 복수 유전율을 얻었으며, 그 이유는 전파계수만을 이용한 복수유전율 측정기법이 반사 계수를 이용한 방법보다 측정오차에 대해 안정적인 결과 값을 제공하였기 때문이다. 또한 역추출 방식으로 유전알고리듬을 적용함으로써 매우 효율적이고 정확한 측정결과 값을 얻을 수 있었다. 제안된 방법을 이용하여 도체입자가 함유된 복합유전체 및 PCB 기판의 복소유전율을 측정하였다.

Keywords

References

  1. A. Ishimaru, Electromagnetic Wave Propagation, Radiation, and Scattering, Prentice-Hall, N J, 1991
  2. W. T. Doyle and I. S. Jacobs, 'Effective cluster model of dielectric enhancement in metal-insulator composites,' J. of Physical Review B, 42, no. 15, 1990
  3. A. M. Nicolson, and G. F. Ross 'Measurement of the intrinsic properties of materials time domain techniques,' IEEE Trans. IM-19, no. 4, pp. 377-382, September 1995
  4. Hewlett Packard Product Note No. 8510-3
  5. W. B. Weir, 'Automatic measurement of complex dielectric constant and permeability at microwave frequencies,' Proceedings of the IEEE, vol. 62, no. 1, pp. 33-36, January, 1974 https://doi.org/10.1109/PROC.1974.9382
  6. J. Musil and F. Zacek, Microwave Measurements of Complex Permittivity by Free space methods and Their Applications, Elsevier, 1986
  7. J. Baker-Jarvis and E.J. Vanzura, 'Improved Technique for Determining complex Per-mittivity with the transmission/Reflection Method,' IEEE Trans. MTT-38, pp.1096-1101, August 1990
  8. D. E. Goldberg, Genetic Algorithms in Search, Optimization, and Machine Learning, Addison Wesley Publishing Company, Inc. 1989
  9. S. Lee and Y. Kuga, 'High permittivity dielectric composite materials,' 2001 IEEE AP-S International Symposium/URSI, July 8-13 2001, Boston, MA