Speckle reduction of echographic images using higher order harmonic components

This paper proposes a novel speckle reduction technique using higher order harmonic components in echoes due to nonlinear propagation of finite amplitude ultrasonic waves. The probe of separation of transmission and reception transducer is used. Especially, the reception transducer is made of PVDF film of broadband characteristics. As a result of experiments with the probe, tenth orders of harmonic components are measured and speckle reduction is confirmed by summation of fundamental components, second, third and fourth order harmonic components.