Broadband transducer technology

The bandwidth characteristic is an important indicator of the transducer. The bandwidth characteristics of the piezoelectric tubes transducer affects the spectral characteristics and waveform of the transmitted signal.Miscellaneous forms of signals and the use of modern signal processing techniques such as pulse compression require that the piezo cylinder ceramic transducer must have sufficient bandwidth or it will signal distortion.it affects the effect of signal processing. It is no exaggeration to say that broadband transducers are the bottleneck of sonar signal processing technology. Without broadband transducers, broadband transducers are so important. broadband design of transducers has become one of the long-term unremitting efforts of scientific research. An important means for the transducer to achieve widthband is to utilize multi-resonant mode coupling, such as longitudinal mode of a longitudinal transducer, radiation mode coupling of a radial head, double excitation mode coupling of a longitudinal transducer and vertical transducer matching layer technology. 

Achieving double longitudinal mode coupling and flexural piezo cylinder ceramic transducer hoist structure double bending mode coupling,which overflow ring transducer radial vibration, liquid cavity resonant mode coupling, multimode cavity coupled broadband transducer, etc.

Here we focus on the vertical broadband transducer. Longitudinal transducers utilize multi-resonant mode coupling to achieve broadband characteristics. It is a three-resonant mode coupled transducer (resonant frequency is 15,25,35kHz, respectively), wherein the 15kHz resonant frequency of Pzt piezoceramic cylinder tube is the longitudinal resonant mode of the piezoelectric ceramic stack excitation transducer, and the 35kHz resonant frequency is the upper end of the smoothing.The longitudinal resistance of the gasket (glass reinforced plastic material) and the intermediate mass of the upper end and the longitudinal structure of the aluminum radiation head substructure. The 25 kHz resonant frequency is the longitudinal resonant mode of two compliant gaskets (glass reinforced plastic material) and two intermediate masses and aluminum radiation head substructures. The transducer achieves a working bandwidth from 13kHz to 37kHz. It is also a three-resonance mode coupled transducer. 

The difference is that a 1/4 wavelength matching layer is formed by a resin material in front of the aluminum radiation head. The function of the matching layer is also to make the overall structure reflect the characteristics of the substructure and have multiple orders and longitudinal vibration resonant mode. In the design of the longitudinal broadband transducer, the compliant gasket is replaced by functional materials, designed as a double-excitation, three-excitation longitudinal broadband transducer with more powerful radiation capability. Double excitation broadband longitudinal transducer is composed of rare earth giant magnetostrictive material and PZT piezoelectric tubular transducer.