| 摘要 |
PURPOSE:To obtain the 1H delay time by means of a 1/2H delay line, by using a piezoelectric element of double-terminal type for both input and output and making the ultrasonic wave go and come back the same route. CONSTITUTION:The high frequency signal supplied from a terminal 5 is branched into the 1st and 2nd signal paths via a coupling capacitor. The 1st signal is fed to the minus input of a differential amplifier 14 through resistances 13 and 15; while the 2nd signal is fed to the plus input of the amplifier 14 through a matching circuit 6, a double-terminal type ultrasonic delay line 7 and a resisttance 16. Such ultrasonic delay line circuit is used as a comb-shaped filter or a delay line. The line 7 has the size of a 1/2H delay line and can obtain the 1H delay time. This contributes to the miniaturization of the delay line circuit. |
