Surface-wave transducer modeling

Equivalent circuit models are developed for surface-wave transducers and their relation to the crossed-field model is shown. The surface wave problem is simplified to obtain a closed form solution, by considering only particle displacements in the sagittal plane. Dynamic variables and the characteristic impedance for piezoelectric transmission lines are defined. The response of an alternate phase array is extended to frequencies other than the synchronous frequency, by considering only the short-circuit current response at first which permits the conformal mapping of the semi-infinite strip and the residual solution of the potential. The admittance matrix of a basic section is obtained along with the corresponding equivalent circuit and a parallel circuit. By duality the transmission line part of this circuit is changed and the crossed-field circuit model is obtained. Over any frequency range of practical interest the performance of the equivalent circuit resembles the crossed-field model so that the established analysis and design procedures apply.