| 摘要 |
PURPOSE: A high directive ultrasonic transducer is provided to form a crenellated shape harmony layer on a radiation plate which is vibrating to higher mode to fit a vibration mode, thereby forming an ultrasonic transducer with a thin thickness which has high radiation efficiency and a high directive property. CONSTITUTION: A high directive ultrasonic transducer comprises a flat type radiation plate(400), a driving unit(410), and a harmony layer(401). The flat type radiation plate radiates ultrasound which vibrates to be higher than a second mode within a medium. The driving unit forces a certain power to a lower surface of the radiation plate and vibrates the radiation plate to be higher than a second mode. The harmony layer is formed to be 1/4 height of a supersonic wavelength at the medium of upper surface of the radiation plate with a positive vibration velocity. The harmony layer has smaller impedance than the material of the radiation plate.
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