| 摘要 |
PROBLEM TO BE SOLVED: To provide a sonar and a method for switching impedance characteristic with which it is possible to suppress the occurrence of reactive power and prevent a reduction in wave transmission efficiency even after being installed in a sonar using environment.SOLUTION: An impedance adjustment circuit 3 outputs, on the basis of an applied adjustment signal, a transmission signal that is inputted to an input terminal whose input impedance is variable. A wave transmitter 4 converts the transmission signal outputted by the impedance adjustment circuit into an acoustic signal, and transmits the converted signal to the outside. A power output control unit 2 measures the phase of impedance at a prescribed frequency as seen on the input terminal side, and supplies an adjustment signal for adjusting its absolute value to within a prescribed value to the impedance adjustment circuit along with the transmission signal.SELECTED DRAWING: Figure 1 |
