Expand bandwidth of composite transducer via matching layer design

ABSTRACT

The bandwidth of composite transducer was successfully expanded via matching layer design. Firstly, the admittance equation of transducer was deduced through combining the equivalent model of 1–3 piezoelectric composite with the electromechanical equivalent circuit of piezoelectric crystal thickness vibration. Then, the relations between bandwidth and the parameters of matching layer were summarized by the conductance curves. Finally, a composite transducer with matching layer was designed and fabricated. Experimental results show that the bandwidth reaches to 56 kHz and the mechanical quality factor Q drops to 1.8. The results are in agreement with the theoretical calculation.

KEYWORDS:

• Piezoelectric composite
• matching layer
• high frequency
• broadband

Funding

This work was supported by the National Natural Science Foundation of China (No. 61471047, 61671068, 11604363), and the Beijing College Innovation Capability Promotion Plan of Beijing Municipal Institutions (No. TJSHG201510772015). The project is also supported by The Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions (No. CIT&TCD201504053).