title: 3-D electrostatic hybrid element model for SAW interdigital transducers.
abstract: In this work, the singular behavior of charges at corners and edges on the metallized areas in SAW transducers are investigated. In particular, it is demonstrated that a tensor product of the commonly used Tchebychev bases overestimates the singularities at corners, and, hence, it cannot be used in a proper boundary element method formulation. On the other hand, it is shown that a simple finite element method-like approach is impractical due to the enormous number of unknowns required to model the electrode's large length-to-width ratio. These considerations are then used for defining a hybrid element model, which combines Tchebychev and linear polynomials over differently meshed domains. Such an approach is shown to suitably account for charge singularities while greatly reducing the number of unknowns. Results are obtained for isotropic and anisotropic substrates for non-periodic configurations.
authors.affiliation: Département LPMO of the Institut Franche-Comté Electronique Mécanique Thermique et Optique-Science et Technologie, Centre National de la Recherche Scientifique UMR 6174, Besançon, France. carlos.jerez@polytechnique.edu
authors.forename: Carlos F
authors.initials: CF
authors.lastname: Jerez-Hanckes
authors.forename: Vincent
authors.initials: V
authors.lastname: Laude
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Nédélec
authors.forename: Raphael
authors.initials: R
authors.lastname: Lardat