Millimeter-Wave Acoustic Transducers

Abstract : The project is aimed at developing a strategy for generating coherent sound waves in solids and liquids at very high frequencies, i.e., above 2000 GHz. Sound waves at these frequencies are important probes for investigating the physical properties of solids and liquids. Our approach is directed toward the use of periodic structures in piezoelectric films of zinc oxide. These multilayer films with alternate layers of piezoelectric active material will serve as efficient transducers if the period of the alternate layers are equal to the wavelength of sound. Multilayer transducers have been fabricated that work at 16, 32 and 96 GHz. Their use is forecasted in a number of applications such as the cryogenic acoustic microscope. Keywords: Sound waves; Microwave frequencies; Multilayer transducers; Piezoelectric films; Cryogenic acoustic microscope; Zinc oxide.