Excitation mechanism and application of continuous-order mode for one-dimensional thickness vibration.

The main method to expand the operating bandwidth of the transducer is by exciting multi-order vibration modes, which develop from the earliest excitation of odd-order modes to the excitation of multi-order continuous modes. However, no detailed theoretical characterization of the excitation mechanism and electroacoustic properties of continuous-order modes has been given. In this paper, the excitation mechanism of continuous-order modes for one-dimensional thickness vibration is studied in detail. From the perspective of analytical characterization, the mathematical and physical conditions of mode excitation are analyzed and extended to continuous-order modes. Partial 1-3 piezocomposite consists of two parts; one part is complete lead zirconate-titanate and the other part is 1-3 composite, which is helpful for exciting continuous-order modes. Based on the excitation mechanism of continuous-order modes, a design method of broadband transducer used of partial 1-3 piezocomposite is proposed, and large bandwidth and good pulse response are obtained. The excitation mechanism of continuous-order modes proposed in this paper provides an idea for the theoretical analysis and design of multi-resonant broadband transducers.