| 摘要 |
PURPOSE:To improve the efficiency of transmission/receiving by connecting a resistor in parallel and an inductor in series with the vibrating element of an ultrasonic wave probe that is equipped with a coaxial cable which transfers transmitting/receiving voltage to the vibrating element. CONSTITUTION:When transmitting ultrasonic wave, a vibrating element 1 is driven by an oscillating part 8 through a resistor 7, a diode 6, a coaxial cable 4 and an inductor 2 and also, both ends of the cable are bypassed to the ground through an inductor 5 and a resistor 3. By resonating in parallel the electrostatic capacity of the inductor 5 and the cable 4, a voltage e3 that is applied to the resistor 3 becomes e3 eg.Z3/(Z3+Z7) by an equivalent circuit shown at a figure and works as a constant voltage source against a piezo-electric element 1 and the inductor 2. When receiving, the oscillating part 8 is separated by the diode 6 and, the inductor 5 and the cable 4 resonate in parallel and the resistor 3, the inductor 2 and an oscillator 1 resonate in series against the receiving signal. Thereby, efficient transmission/receiving is realized. |
