摘要:
A measuring ultrasonic wave transmitter comprises a negative immitance converter inserted between an ultrasonic transmitting transducer and a drive amplifier for driving the transmitting transducer. The output impedance of the drive amplifier, the damping impedance of the transmitting transducer and the impedance between the transmitting transducer and the drive amplifier are offset by the negative impedance caused by the negative immitance converter. A measuring ultrasonic wave receiver comprises a negative immitance converter inserted between a receiving transducer and a pre-amplifier for amplifying the output of the receiving transducer. The damping admittance of the receiving transducer and the load admittance of the receiving transducer are offset by the negative admittance caused by the negative immitance converter.