| 摘要 |
PURPOSE:To omit a bridging circuit for operation, and a variable resistance for adjusting an original signal level, by providing one piezoelectric plate on a foundation earth electrode formed on the surface of a delay medium, and forming a groove along the lengthwise direction or the width direction, on its surface. CONSTITUTION:In the center part in the lengthwise direction of a piezoelectric plate 7, a groove 10 is formed over the whole length in the width direction, and upper electrodes 11a, 11b are formed, to which input/output terminals 5a, 6a are connected. The piezoelectric plate 7 is divided into blocks 7a, 7b which are not coupled electrically but are coupled acoustically only, by the groove 10. By a high-frequency signal applied to the input terminals 5a, 5b, an ultrasonic wave energized by one piezoelectric plate 7a not only reaches the other piezoelectric plate 7b through a delay medium 8, but also is directly transferred to the other piezoelectric plate 7b from one piezoelectric plate 7a, and its transfer quantity is varied by depth of the groove 10. |
