Journal of Sensor Science and Technology (센서학회지)

The Korean Sensors Society (한국센서학회)
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Development of an Impedance Matching Layer in an Ultrasound Transducer with Gradient Properties

  • Received : 2018.10.02
  • Accepted : 2018.11.27
  • Published : 2018.11.30
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Abstract

The piezocomposite transducer is widely used because it is highly efficient in transforming electric energy into mechanical energy, and its frequency range is broader than that of other types of ultrasound transducers. A general piezocomposite transducer is composed of an acoustic lens, impedance matching layers, piezoelectric materials, and backing layers. When an input voltage is applied to a piezoelectric material as an active material, it generates sound waves while vibrating. At that time, an impedance matching layer helps the sound waves to propagate forward while reducing the impedance mismatch that may occur at the interface between the active material and its front material. The impedance mismatch has a negative effect on the signal of an ultrasound transducer; thus, it is important to design a matching layer to overcome the issue. In this study, an optimized feature of a matching layer with gradient properties is studied. An objective function is defined to minimize both the average and the deviation of the reflection coefficients that are functions of the frequencies. As a result, an improvement in the signal characteristics with respect to the sensitivity and bandwidth is reported.

Keywords

HSSHBT_2018_v27n6_374_f0001.png 이미지

Fig. 1. Scheme of piezocomposite with (a) no matching layer, (b) conventional single matching layer, and (c) proposed matching layer.

HSSHBT_2018_v27n6_374_f0002.png 이미지

Fig. 3. The sensitivity and bandwidth results for transducers with (a) no matching layer, (b) conventional single matching layer, and (c) proposed matching layer.

HSSHBT_2018_v27n6_374_f0003.png 이미지

Fig. 2. (a) Volume fraction of filler, and (b) Characteristic impedance along /x/L.

References

  1. C. S Desilets, J. D. Fraser, and G. S. Kino, "The design of efficient broad-band piezoelectric transducer", IEEE Trans. Sonics Ultrason., Vol. UFFC-25, No. 3, pp. 115-125, 1978.
  2. R. E. McKeighn, "Optimization of boradband transducer designs by use of statistial design of experiments", IEEE Trans. Ultrason. Ferroelectr. Freq. Control, Vol. 43, No.1, pp. 63-70, 1996. https://doi.org/10.1109/58.484464
  3. M. I. Haller and B. T. Khuri-Yakub, "Tapered acoustic matching layers", Proc. IEEE Ultrason. Symp., Vol. 1, pp. 505-508, Baltimore, USA, 1993.
  4. S. Sato, H. Katsura, and K. Kobayashi, "Experimental investigation of phased array using tapered matching layers", Proc. IEEE Ultrason. Symp., Vol. 2, pp. 1235-1238, Munich, Germany, 2002.
  5. Z. Li, D. Q. Yang, S.L. Liu, S. Y. Yu, M. H. Lu, J. Zhu, S. T. Zhang, M. W. Zhu, X. S. Gio, H. D. Wu, X. L. Wang, and Y. F. Chen, "Broadband gradient impedance matching using an acoustic metamaterial for ultrasonic transducers", Sci. Rep., Vol. 7, 42863, 20175. https://doi.org/10.1038/srep42863
  6. X. Dongyu, C. Xin, and H. Shifeng, "Investigation on fabrication and property of acoustic gradient composites", Compos. Sci. Technol., Vol. 122, No. 18, pp. 90-96, 2016. https://doi.org/10.1016/j.compscitech.2015.11.024
  7. L. Spicci, "FEM simulation for pulse-echo performances of an ultrasound imaging linear probe", Proc. COMSOL conf. Rotterdam, Rotterdam, Netherlands, 2013.
  8. A. Austeng, "Sparse 2D arrays for 3D phased array imaging- design methods", IEEE Trans. Ultrason. Ferroelectr. Freq. Control, Vol. 49, No. 8, pp. 1073-1086, 2002. https://doi.org/10.1109/TUFFC.2002.1026019
  9. W. Voigt, "Uber die Beziehung zwischen den beiden Elastizitatskonstanten Isotroper Korper", Wied. Ann., Vol. 38, pp. 573-587, 1889.
  10. A. Reuss, "Berechnung der Fliessgrense von Mischkristallen auf Grund der Plastizitätsbedingung für Einkristalle", Z. Angew. Math. Mech., Vol. 9, pp. 49-58, 1929. https://doi.org/10.1002/zamm.19290090104
  11. C. C. Chamis, "Mechanics of composite materials: past, present, and future", J. Compos. Technol. Res., Vol. 11, pp. 3-14, 1989. https://doi.org/10.1520/CTR10143J
  12. J. C. Halpin, J. L. Kardos, "The Halpin-Tsai equations: A review", Polym. Eng. Sci., Vol. 16, No. 5, pp. 344-352, 1976. https://doi.org/10.1002/pen.760160512
  13. M. de Jong, W. Chen, T. Angsten, A. Jain, R. Notestine, A. Gamst, M. Sluiter, C. K. Ande, S. van der Zwaag, J. J Plata, C. Toher, S. Curtarolo, G. Ceder, K. A. Persson, and M. Asta, "Charting the complete elastic properties of inorganic crystalline compounds", Sci. Data, Vol. 2, 150009, 2015. https://doi.org/10.1038/sdata.2015.9
  14. D. M. Pozar, Microwave Engineering, 3rd ed., John Wiley & Sons, New York, pp. 49-90, 2011.