| 摘要 |
PROBLEM TO BE SOLVED: To form a large spherical wave by transmitting waves with time delay from many elements to a linear transducer, based on a specified display pattern, forming many limited plane waves from many formed waves and superposing the plane waves. SOLUTION: A virtual linear transducer on the axis X does not really exist and elements on the axis X transmit spherical waves with their respective time delays, based on a display pattern, thereby forming many limited plane waves which are superposed to form a spherical wave. According to the setting content of the display pattern, the position of the linear transducer is shifted from the center of the spherical wave to avoid the energy concentration phenomenon. Thus the formed spherical wave can travel a long distance and the signal to noise ratio can be improved.
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