To provide a multilayer piezoelectric transducer that is controlled by an electric field.
An ultrasonic transducer array incorporates low dielectric constant materials so as to limit an electric field of a stack of its piezoelectric ceramic layer. Edge segments extended perpendicularly made of a material with a low dielectric constant are formed to an opposing edge of the multilayer structure. The electric field is limited to the piezoelectric ceramic material with a high dielectric constant by the regions made of the material with the low dielectric constant and the electric field is pointed out vertically at the piezoelectric ceramic material with the high dielectric constant. In this method, when a voltage is applied between electrodes, the piezoelectric induction distortion is nearly directed vertically as a whole. Thus, the spurious radiation mode can substantially be reduced.
GLENN WILDES DOUGLAS
VENKATARAMANI VENKAT SUBRAMAN
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