Simulation of short LSAW transducers including electrode mass loading and finite finger resistance

    Authors

    K. J. Gamble;D. C. Malocha

    Abbreviated Journal Title

    IEEE Trans. Ultrason. Ferroelectr. Freq. Control

    Keywords

    INTERDIGITAL TRANSDUCERS; SAW; Acoustics; Engineering, Electrical & Electronic

    Abstract

    The theory for the 2-D numerical analysis of acoustic wave generation from finite length leaky surface acoustic wave (LSAW) transducer structures is presented. The mass loading of the electrodes is incorporated through the use of the finite element method (FEM). The substrate is modeled using both analytical and numerical means. The advantages of this simulation are twofold. First, it is capable of extracting the individual bulk wave conductances from the overall conductance of a given device. At large distances from the transducer, the angular distribution of power radiated relative to the substrate surface can then be calculated for each of the three possible bulk wave polarizations. The second advantage of the simulation is that the effect of finite electrode resistance is included through the use of a series equivalent resistance for each electrode in the structure. Once the resistance for each electrode in the structure has been determined, the overall effect on the device admittance is modeled by applying a constrained minimization process to the electrical boundary conditions of the transducer. To conclude the paper, the simulation will be compared against the experimental admittance of a 37-finger uniform transducer with a metalization ratio of 0.5 on 42degrees LiTaO3. The agreement between theory and experiment is excellent.

    Journal Title

    Ieee Transactions on Ultrasonics Ferroelectrics and Frequency Control

    Volume

    49

    Issue/Number

    1

    Publication Date

    1-1-2002

    Document Type

    Article

    Language

    English

    First Page

    47

    Last Page

    56

    WOS Identifier

    WOS:000173531300007

    ISSN

    0885-3010

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