High-frequency acoustic characterization of porous lead zirconate titanate for backing applications

Porous piezoelectric ceramics are often integrated as constitutive elements in several devices such as ultrasound transducers. For high-frequency (HF) applications (i.e., >20 MHz), unpoled, porous lead zirconate titanate (PZT) can be used as a backing. The porosity content allows the acoustical impedance value to be adjusted but it also affects the acoustic attenuation according to the size and shape of the pores in the material. For transducer design, it is essential to know these properties. At high frequency, the corresponding experimental set-up is often difficult to implement with standard reflection or transmission method. In this work, we propose an original and easy way to measure these properties directly at the operating frequency of the transducer.