| 摘要 |
<p>Ultrasonic transducer with a selectable beamwidth comprising a body of piezoelectric material in the form of an annulus (21) having an outer diameter D and a thickness T. The body has proximal and distal generally planar parallel surfaces and a centrally disposed hole extending therethrough. The body has a cylindrical wall with a width W extending from the hole to the outer diameter. The transducer is capable of operating at low and high resonance being determined by the diameter D and an aspect ratio of D/T and the high frequency resonance being determined by the thickness T and an aspect ratio of W/T.</p> |
