Electrical generator or motor structure – Non-dynamoelectric – Piezoelectric elements and devices
Patent
1994-05-20
1995-03-07
Manuel, George
Electrical generator or motor structure
Non-dynamoelectric
Piezoelectric elements and devices
310320, 12866203, H01L 4108
Patent
active
053961439
ABSTRACT:
An ultrasonic transducer for controlling an elevation aperture utilizes the electric field-induced polarization properties of relaxor ferroelectric materials. The Curie temperature of the material is typically close to room temperature, so that the application of a bias voltage provides piezoelectric activity. By varying the thickness of a dielectric layer that spaces apart the relaxor ferroelectric material from an electrode or providing the bias voltage, the piezoelectric activity can be tailored. That is, degrees of polarization of the relaxor ferroelectric material are varied spatially in correspondence with changes in thickness of the dielectric layer. The effective elevation aperture of the transducer can be varied by adjusting the bias voltage.
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Greenstein Michael
Melton, Jr. Hewlett E.
Seyed-Bolorforosh Mir S.
Hewlett--Packard Company
Manuel George
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