Calculation of Interdigital Transducer Interaction with SAWs and BAWs

  • F. Seifert
  • A. R. Baghai-Wadji
  • K. C. Wagner
  • G. Kovacs
Part of the Springer Series on Wave Phenomena book series (SSWAV, volume 7)

Abstract

Since the interdigital transducer (IDT) was used by WHITE and VOLTMER /1/ in 1965 to excite surface acoustic waves (SAWs) on plane piezoelectric substrates, signal processing devices based on this effect have evolved to a high degree of maturity and are described comprehensively in the book by MORGAN /2/. These devices are fabricated in a one step planar metal layer technology and consist mainly of launching (L) and receiving (R) — IDTs whose structure determines the electric filter characteristic. Simple physical reasoning shows, that the IDT’s SAW impulse response h(t) in a first approximation is given by its structure (i.e. the finger arrangement and mutual finger overlap, called apodisation). Fourier transform (FT ) yields the transfer function \(\bar H\)(w) of the IDT:
$$\bar H\left( w \right) = F{T^ - }\left( {h\left( t \right)} \right).$$
(1)

Keywords

Quartz Anisotropy Convolution Acoustics Line Source 

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References

  1. /1/.
    R.M. White and F.W. Voltmer, “Direct Piezoelectric Coupling to Surface Elastic Waves”,Appl.Phys.Lett. 7, pp.314–316 (1965).CrossRefADSGoogle Scholar
  2. /2/.
    D.P. Morgan, “Surface Wave Devices for Signal Processing”, Elsevier 1985.Google Scholar
  3. /3/.
    R.H. Tancrell and M.G. Holland, “Acoustic Surface Wave Filters”, Proc. IEEE 59, pp.393–409 (1971).CrossRefGoogle Scholar
  4. /4/.
    C.S. Hartmann et.al., “Impulse Model Design of Acoustic Surface Wave Filters”,IEEE Trans. MTT-21, pp.162–175 (1973).Google Scholar
  5. /5/.
    R.F. Milsom, N.H. Reilly AND M. Redwood, “Analysis of Generation and Detection of Surface and Bulk Acoustic Waves by Interdigital Transducers”, IEEE Trans., SU-24, No.3, May 1977, pp. 147–166.Google Scholar
  6. /6/.
    A.M. Hussein and V.M. Ristic, “The Evaluation of the Input Admittance of SAW Interdigital Transducers”, J.Appl.Phys., Vol.50, No.7, July 1979, pp.4794–4801.CrossRefADSGoogle Scholar
  7. /7/.
    A.R. Baghai-Wadji, “Berechnung der Quellenverteilung zur Anregung von akus-tischen Wellen in Oberfliichenwellenfiltern”, Dr.techn. thesis, Techn. Univ. Wien 1987.Google Scholar
  8. /8/.
    A.R. Baghai-Wadji, S. Selberherr, F. Seifert, “On the Calculation of Charge,Electrostatic Potential and Capacitance in Generalized Finite SAW Structures”, IEEE SU-Symp. 1984, Proc. pp.44–48.Google Scholar
  9. /9/.
    A.R. Baghai-Wadji et al., “Rigorous 3D Electrostatic Field Analysis of SAW Transducers with Closed-Form Formulae”, IEEE SU-Symp. 1986, Proc. pp.23–27.Google Scholar
  10. /10/.
    A.R. Baghai-Wadji et al., “Two Dimensional Green’s Function of a Semi-Infinite Anisotropic Dielectric in the Wavenumber Domain”,IEEE Trans. UFFC-3, May 1986, pp.315–317.Google Scholar
  11. /11/.
    K.C. Wagner et al., “Interdigital Transducer Interaction with SAWs and BAWs,IEEE SU-Symp.1987, Proc. to appear spring 1988.Google Scholar
  12. /12/.
    Liu Yuan, Wang Cheng-Hao and Ying Chong-Fu, “General Two-dimensional Planar Transducers and Blazed Array-Like Interdigital Transducer”, Proc. IEEE Ultrason. Symp. 1986, Williamsburg, USA, pp.129–132.Google Scholar
  13. /13/.
    A.R. Baghai-Wadji, O. Männer, S. Selberherr and F. Seifert, “Analysis and Measurement of Transducer End Radiation in SAW Filters on Strongly Coupling Substrates”,in Proc. 1st European Frequency and Time Forum, Besancon, France, 1987, pp.315–319.Google Scholar
  14. /14/.
    O. Männer, “Knotenvariablen Analyse von Oberfidchenwellenfilter”, Dr. techn. thesis, Techn. Univ. Wien, 1987.Google Scholar
  15. /15/.
    B. Fleischmann, W. Ruile and G. Riha, “Rayleigh-Mode SAW Filters on Quartz for the Timing Recovery at Frequencies above 1 GHz, IEEE SU-Symp. 1986, Proc. pp.163–167.Google Scholar
  16. /16/.
    W.R. Mader, C. Ruppel and E. Ehrmann-Falkenau, “ Universal Method for Compensation of SAW Diffraction and other Second Order Effects, IEEE SU-Symp. 1982, Proc. pp.23–34.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1988

Authors and Affiliations

  • F. Seifert
    • 1
  • A. R. Baghai-Wadji
    • 1
  • K. C. Wagner
    • 1
  • G. Kovacs
    • 1
  1. 1.IAEETechnical UniversityWienAustria

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