| 摘要 |
PURPOSE:To extend the effective operating range of the transducer in the water and to improve the detection capability for small targets by connecting an impedance matching transformer at the connecting position of a coaxial cable and two oscillators in parallel connection. CONSTITUTION:The impedance matching transformer 5 is provided at the connecting position between the coaxial cable 4 and the two oscillators 2. The impedance of the two ceramic oscillators 2 of PZT material whose diameter is 80phi in parallel connection in approximately 230OMEGA, while that of the coaxial cable 4 is 75OMEGA. The transformer 5 whose outer diameter is 20phi consists of a troidal core made of ferrite and the primary and secondary windings whose winding ratio is 1:1.74. The improvement in the total sensitivity of transmission and reception due to the increase of the radiating area of the oscillators in case whose diameter are changed from 60phi to 80phi, is 10db. Therefore, the actual effect due to the impedance matching comes to be 11db.
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