The design of a kind of free-flooded ring transducer used in underwater communication

Over the past several years, Hangzhou Applied Acoustics Research Institute(HAARI) has developed the ring transducer, including the air-backed ring transducer(ABRT) and free-flooded ring transducer(FFRT). A previous paper [1] described a kind of transmit-receive air-backed ring transducer with radially poled ceramic. This paper reports on our successful efforts to develop a broadband segmented free-flooded ring transducer with a circumferentially poled ceramic. Broadband response is achieved by coupling the cavity resonance mode and the circumferential resonance mode. The maximum diameter of the transducer is 90mm (without mounting base). As a transmit-receive transducer, the maximum of the Transmitting Voltage Response (TVR) is 141.3 dB//μPa@1m/V, @12.8kHz. The frequency band with transmitting response decreasing 3dB is from 9.6kHz to 18.4kHz. The maximum of the Receiving Voltage Response (RVS)in free field is -179 dB//V/μPa, @13.2kHz. The frequency band width receiving response decreasing 3.3dB is from 8.6kHz to 18.8kHz. The transducer shows great promise as a broadband, high efficiency, high-power underwater acoustic transceiver for deep water applications in excess of several thousand meters and with an omi-directionally beam pattern in horizon.