A special ultrasonic transducer is described for the mean frequency estimation in local attenuation measurement. Unlike the classical focusing transducer, this probe has a diffraction pattern that is frequency independent within its main lobe, so that the mean frequency of the signal received by any scatterer does not depend on its location in the ultrasonic field. A-lines have been computed for different simulated media, both with this probe and with a classical focusing monotransducer. The results of the mean frequency processing exhibit some improvements, especially when small volumes are considered and when inhomogeneities are introduced inside the medium
Date of Conference: 9-12 Nov 1989