| 摘要 |
PURPOSE:To attain low cost and small size by using input/output transducers of an ultrasonic wave delay line as one, splitting electrodes at front and rear sides of the transducer into two at a part not overlapped in the broadwise direction and arranging the input and output terminals to an electrode pair having frong and rear counter parts respectively. CONSTITUTION:Parts of an input/output transducer 11 corresponding to electrodes 12 and 16 act as a function transmitting and receiving an ultrasonic wave propagated in a delay medium 21 as the input and output transducers and a counter part 18 couples input and output electrodes 13, 15 in terms of capacitance. Thus, an input signal is converted into an ultrasonic wave, which is propagated in the delay medium 12 and converted again into an electric signal, outputted with a prescribed time of delay and a bypass signal is also outputted by the capacitive coupling, a comb line filter acting like that is obtained. The electrode 13 is deleted or added by a part of a separation slit 14 so as to change the static capacitance between the input and output electrodes, and the bypass signal level is adjusted so as to be made coincident with a delay signal level. |
