| 摘要 |
PURPOSE:To generate a directional beam only of a main pole beam by combining two ultrasonic wave receivers and shaping, multiplying and integrating circuits. CONSTITUTION:Two non-directional ultrasonic wave receivers 1 and 2 are connected through amplifiers 3 and 5, a multiplying circuit 4 and a shaping circuit 6 with an integrating circuit 7. As a result, the received signal of the receiver 1 is amplified by the amplifier 3 and then is fed to the multiplying circuit 4. On the other hand, the signal received by the receiver 2 is amplified by the amplifier 5 and then is fed to the shaping circuit 6. This circuit 6 feeds out the square waves which have their higher and lower level terms continuing during the half period of the received signals so that the square waves are fed out to the multiplying circuit together with the received signals from the amplifier 3. Then, the multiplying circuit 4 multiplies the square waves and the received signals to feed out the received signals in the same polarity while the square waves are positive and to invert and feed out the received signals in the opposite polarity while the square waves are negative so that they are integrated by the circuit 7. As a result, the output of the circuit 7 is fed out to the shaping circuit so that only the main pole voltage is taken out to attain the desired object. |
