**6. Conclusions**

A novel type of cascade-connected transducer is present. Its performances are predicted through finite element method, especially the behavior of cross-beams. Several prototypes with different segments are manufactured. The relevant tests show that the cascade-connected transducer can satisfy the requirements for the transmitting or receiving application in the acoustic telemetry system while drilling. In summary, the following conclusions can be obtained.


**Funding:** This research was funded by the National Key Laboratory, gran<sup>t</sup> number JCKY2018207CD04.

**Acknowledgments:** The author acknowledges the National Key Research and Development Program of China, gran<sup>t</sup> number 2016YFF0200902, for the experiment support.

**Conflicts of Interest:** The author declares no conflict of interest.
