Periodic Green's functions analysis of SAW and leaky SAW propagation in a periodic system of electrodes on a piezoelectric crystal

A method of periodic Green's functions with a propagation factor exp(i/spl beta/x), unknown in advance, is used to calculate dispersion curves and attenuation coefficients for Rayleigh- and leaky- waves propagating in a periodic system of thin electrodes on a piezoelectric surface. To describe the charge distribution on the electrodes both a step approximation and Chebyshev polynomials are used, the last being more adequate in most cases. Numerically determined values of the Green's function are used and interpolated either linearly or using a modified variant of Ingebrigtsen's formula. Such basic parameters as stopband width, stopband center frequency, wave velocity and attenuation in the stopband are found. These parameters can be used in the coupling-of-modes (COM) analysis and design of SAW devices. The analysis includes bulk wave radiation and scattering. The dependence of the corresponding attenuation coefficient on frequency is determined. Results obtained allow the determination directly and properly of the COM parameters and the design of SAW devices having large number of electrodes most precisely and rapidly. Numerical results for Rayleigh waves on YZ-LiNbO/sub 3/ and leaky waves on 36/spl deg/YX-LiTaO/sub 3/ substrates are presented.<<ETX>>

[1]  M. Onoe,et al.  Determination of Elastic and Piezoelectric Constants for Crystals in Class (3m) , 1967 .

[2]  Clemens Ruppel,et al.  Improved material constants for LiNbO/sub 3/ and LiTaO/sub 3/ , 1990, IEEE Symposium on Ultrasonics.

[3]  K. Ingebrigtsen,et al.  Surface Waves in Piezoelectrics , 1969 .

[4]  Y. Gulyaev,et al.  REVIEWS OF TOPICAL PROBLEMS: Propagation of acoustic surface waves in periodic structures , 1989 .

[5]  Y. Zhang,et al.  Theoretical determination of the pseudo surface acoustic wave characteristic parameters , 1991, IEEE 1991 Ultrasonics Symposium,.

[6]  C. S. Hartmann,et al.  A generalized impulse response model for SAW transducers including effects of electrode reflections , 1988, IEEE 1988 Ultrasonics Symposium Proceedings..

[7]  Michel Feldmann,et al.  Surface Acoustic Waves For Signal Processing , 1989 .

[8]  D. Malocha,et al.  Closed form solutions for multistrip coupler operation including the effects of electrode resistivity , 1990, IEEE Symposium on Ultrasonics.

[9]  T.J.B. Swanenburg,et al.  Electric coupling properties of acoustic and electric surface waves , 1971 .

[10]  H. Skeie,et al.  Acoustic surface waves in piezoelectric materials with periodic metal strips on the surface , 1973 .

[11]  Hiroshi Shimizu,et al.  SH-Type and Rayleigh-Type Surface Waves on Rotated Y-Cut LiTaO 3 , 1977 .

[12]  C. Mecklenbrauker,et al.  Green's function applications in SAW devices , 1991, IEEE 1991 Ultrasonics Symposium,.

[13]  K. Hashimoto,et al.  Interaction of High-Coupling Leaky SAW with Bulk Waves Under Metallic-Grating Structure on 36° YX-LiTaO3 , 1985, IEEE 1985 Ultrasonics Symposium.

[14]  J. C. Andle,et al.  Improved Accuracy for Determining SAW Transducer Capacitance and K2 , 1987, IEEE 1987 Ultrasonics Symposium.

[15]  Ken-ya Hashimoto,et al.  Derivation of coupling-of-modes parameters for SAW device analysis by means of boundary element method , 1991, IEEE 1991 Ultrasonics Symposium,.

[16]  H. Haus,et al.  Analysis of Metal-Strip SAW Gratings and Transducers , 1985, IEEE Transactions on Sonics and Ultrasonics.

[17]  D Hen.  GENERALIZED GREEN'S FUNCTIONS OF SURFACE EXCITATION OF ELASTIC WAVE FIELDS IN A PIEZOELECTRIC HALF-SPACE , 1985 .

[18]  P. V. Wright,et al.  A new generalized modeling of SAW transducers and gratings , 1989, Proceedings of the 43rd Annual Symposium on Frequency Control.

[19]  C. S. Hartmann,et al.  Experimentally determining the transduction magnitude and phase and the reflection magnitude and phase of SAW SPUDT structures , 1990, IEEE Symposium on Ultrasonics.

[20]  I. S. Gradshteyn,et al.  Table of Integrals, Series, and Products , 1976 .

[21]  M. Redwood,et al.  Analysis of Generation and Detection of Surface and Bulk Acoustic Waves by Interdigital Transducers , 1977, IEEE Transactions on Sonics and Ultrasonics.

[22]  Y. Shui,et al.  Analysis of leaky-surface-wave propagating under periodic metal grating , 1990, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[23]  E.G.S. Paige,et al.  Surface-Wave Devices for Signal Processing , 1986 .

[24]  H. Skeie,et al.  A method for analyzing waves in structures consisting of metal strips on dispersive media , 1973 .