ULTRASONIC TRANSDUCER WITH BACKING HAVING SPATIALLY SEGMENTED SURFACE

摘要

Methods and devices are provided for suppressing reverberations within an ultrasound transducer with a backing whereby the backing may not sufficiently attenuate the acoustic energy by means of acoustic absorption and scattering alone. At least a portion of a surface of the backing is segmented into a plurality of levels defined by surface segments. The levels may be are spatially offset so that acoustic reflections from the segmented surface are spread out in time, thereby decreasing the net amplitude of the internally reflected waves as they interact with the piezoelectric layer. Adjacent (neighbouring) levels may be spatially offset by a longitudinal distance equaling approximately an odd number multiple of a quarter of an operational wavelength of the transducer, so that destructive interference occurs from acoustic waves reflected from adjacent levels. Various example configurations of segmented surfaces are described, and methods for selecting a profile of a segmented surface are provided.

主权项

1. An ultrasonic transducer comprising:
an active layer; and a backing having a proximate surface that is proximate to said active layer, and a further surface therebelow, wherein at least a portion of said further surface is a segmented surface; wherein said segmented surface comprises a plurality of approximately planar segments, each segment being approximately parallel to said proximate surface; and wherein at least two of the segments are spatially offset in a longitudinal direction that is approximately perpendicular to said proximate surface, thereby defining two or more levels of said segmented surface, such that each level has a different backing thickness associated therewith.