Accurate evaluation of the real and imaginary material constants for a piezoelectric resonator in the radial mode

Abstract The standard IEEE procedure for determining the piezoelectric, dielectric, and elastic constants associated with the radial mode resonance of piezoelectric materials treats these constants as real rather than complex quantities. This approach is valid in the case of piezoelectric materials with low losses such as Lead Zirconate Titanate. However new lossy materials, such as ceramic-polymer composites, are becoming important to transducer designers. For such materials the losses can be taken into account by treating the constants as complex quantities. This paper presents a method to determine the complex form of the above constants. These constants are calculated from the experimental values of the first and second series resonance frequencies, the first parallel resonance frequency and appropriate half band frequencies and the low frequency admittance of the material, all of which can be measured on one disk sample. The method has also been used to automate the IEEE procedure for determining the...