Design Techniques for Improving the Uniformity and Long-time Stability of Ceramic Transducers.

摘要

Piezoelectric ceramics have found wide spread application in many sonar transducer designs, and although tens of thousands of ceramic transducers of various types have been built over the past decade, there is considerable ambiguity regarding the variations in their performance characteristics under different environments. There has been very little authoritative engineering data available to indicate the exact behavior of the various types of ceramics under varying conditions of use, and in the absence of such data, many transducer designs have proved disappointing in their reliability over long periods of time. Some of the more difficult problems encountered in the design and manuafacture of ceramic transducers concern the achievement of uniformity and long-time stability of the elements, especially for such critical applications in which beam forming networks are employed with the structures. There are two general classes of inherent difficulties that must be overcome; namely, to neutralize the relatively large variations in sensitivity and impedance of the ceramics during the initial production of the transducer elements, and to minimize the variations in aging characteristics that occur among the ceramic elements over the useful life of the transducer.