Ultrasonic Transducer Array with Apodized Elevation Focus

摘要

An ultrasonic transducer array 10 is provided having a plurality of transducer elements 12 aligned along an array axis in an imaging plane. Each transducer element 12 includes a piezoelectric substrate 24 and further includes a back electrode 32 provided on the back side of the substrate and a patterned front electrode 30 provided on the front side of the substrate. A conductive or metallic negative matching layer 26 is disposed on top of the patterned front electrode 30. The front electrode 30 is patterned along a vertical axis orthogonal to the imaging plane, in particular to apodize the emitted ultrasound beam in the vertical plane. The pattern preferably follows a predetermined taper weighting function close to the hamming weighting function. Slots oriented parallel to the array axis are cut into the front surface of the piezoelectric substrate 24 to form a plurality of sub-elements. It also improves beam apodization by separating portions of the piezoelectric substrate on which the patterned front electrode is not disposed.