| 摘要 |
An ultrasonic transducer utilizes an acoustic transmission line to increase the sensitivity of both the transmitting response and the receiving response. The resonant element of the transducer could employ a ceramic disc operating in the radial resonance mode for its transduction means, or it could be a half wavelength resonator utilizing a forward transmission line, a rear transmission line, and a non-resonant ceramic for transduction. The shape of the forward transmission line is designed to generate the desired acoustic radiation pattern at the frequency of resonance, which could be a broad or narrow conical beam or a fan shaped beam. A sealed housing structure is disclosed that contains the forward transmission line that is acoustically disconnected from the rest of the housing. This housing provides improved environmental protection and allows for easy mounting of the transducer without effecting its electroacoustic response characteristics. |
