| Popis: |
The frequency response of a multilayer semiconducting piezoelectric transducer is obtained algorithmically. The multilayer transducer is first reduced to a conventional three‐port structure by defining recursively the mechanical impedance loading each face of the piezoelectric layer. Electromechanical power conversion theory is then used to obtain the transducer loss. Computed results for the performance of multilayer transducers composed of a 1.5‐μ‐thick ZnO film and other metallic layers illustrate the use of this theory in the design of microwave ultrasonic transducers. The effects of finite resistivity, contact resistance, and different tuning conditions are described. The possibility of frequency‐response shaping by using a multilayer is demonstrated by showing that an unusually broad‐bandwidth transducer is obtained for an Au‐ZnO‐Au‐Al structure. |
