Design and experiment of an acoustic transducer for underwater navigation

This paper describes a development of a broad band underwater acoustic transducer for Doppler Velocity Log(DVL). The transducer uses thickness vibration mode of a disk type piezoelectric(PZT) ceramic. Three types of transducers, each having different configuration of acoustic impedance matching layer and backing are composed. Transmitting voltage response(TVR), receiving voltage sensitivity(RVS) and bandwidth of the transmission for the three types of acoustic transducers are evaluated. The test shows that the transducer with the configuration of three matching layers and a lossy backing results the best performance among the three types. From the test results, the effects of the acoustic impedance matching layer and backing are discussed.