Admittance Measurement Accuracies Required to Determine Nonlinear Behavior in Sonar Transducers.

摘要

The gain-bandwidth method is an admitttance measurement technique which may be used to indicate nonlinear behavior in ferroelectric ceramics. In applying the gain-bandwidth method or a simple plot of admittance versus frequency as practical measures of nonlinearity in ceramic sonar transducers, experimental measurement inaccuracies must be considered. An expression was derived from experimental data to approximate the error associated with frequency determination on an admittance circle plot as a function of admittance measurement accuracy. This expression was included in error analyses which revealed that the expected accuracy with which the gain-bandwidth may be used in determining nonlinear behavior in ceramic transducers is proportional to the admittance measurement accuracy and the mechanical quality factor of the transducer. Results indicate that admittance measurement errors cause extreme difficulty in the detection of nonlinearities in transducers which exhibit low mechanical quality factors typical of high-power sonar systems. (Author)