摘要 |
The invention is an improvement to the linear array transducer and the annular array transducer. The improvement lies in the invention's capability to produce a phase shifted wave across each segment of the composite transducer and in so doing, better match the ideal phase shift for aiming or focussing acoustic waves. The invention comprises transducer segments which each have at least one resistive electrode; the other electrode may be a standard highly conductive one. An electrical drive signal is applied to one border of each resistive electrode, and as the electrical drive signal propagates across the resistive electrode, it interacts with the capacitance of the piezoelectric element below and has its phase gradually shifted. As a result, the transducer segment produces an acoustic wave which has gradually varying phase, and this varying phase approximates the curvature of the ideal phase shift pattern.
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