| 摘要 |
PURPOSE:To continuously vary a delay time, by combining two surface acoustic wave transducers being in a reverse relation to each other as to the extent of variation of the energy ratio in each direction of surface acoustic waves proceeding in both the directions. CONSTITUTION:When a signal which is applied to the first terminal t1 through a phase shifter 6 leads the second terminal t2 by a phase angle of 90 deg., surface acoustic waves are generated in the right direction only and the left direction only, in a transducer 8 of the first group on the left, and a transducer 9 of the second group on the right side, respectively. On the other hand, when the signal which is applied to the first terminal t1 lags the second terminal t2 by a phase angle of 90 deg., the surface acoustic waves generated from the transducers 8, 9 of both the groups proceed in reverse. When a phase difference of the first terminal t1 and the second terminal t2 is between 90 deg. and -90 deg., the quantity of waves proceeding in the right direction from the transducers 8, 9 of both the groups are varied continuously by said value. Accordingly, a delay time of an electric signal among the transmitting and receiving transducers 8, 9 and 10 is varied continuously within the time when the surface acoustic wave proceeds to the transducer 9 on the right side from the transmitting transducer 8 on the left side, by varying a phase difference between the terminals t1, t2. |
