| 摘要 |
PURPOSE:To obtain a transducer which excites plural pulse mode longitudinal waves with desired weights by providing a thin-film linar conductor of zigzag form on an amorphous magnetostrictive thin plate and applying d.c. bias magnetic fields in a desired distribution. CONSTITUTION:The amorphous magnetostrictive transducer is constituted by the zigzag form coil 6 of a fixed spacing which is provided on an amorphous magnetostrictive thin plate 1 of a large magnetostrictive constant and coupling coefficient and has a conductor width larger than the plate thickness of the thin plate 1 and the solenoid coil 8 which is distribution wound in the advancing (longitudinal) direction of elastic waves for the purpose of application of bias magnetic fields. When current is flowed in this coil 8, bias magnetic fiels having a certain distribution in the longitudinal direction are generated, hence the distribution of coulling coefficients having a relation to this are obtained, and the elastic strain waves excited by the high frequency electric signals of the coil 6 are obtained as the approximately constant spacing elastic wave group wherein respective crest values are determined at a desired ratio by the distribution bias magnetic fields in accordance with the distribution of the coupling coefficients. |
