Multiple matching scheme for broadband 0.72Pb(Mg_(1/3)Nb_(2/3))O_3-0.28PbTiO_3 single crystal phased-array transducer

摘要

Lead magnesium niobate-lead titanate single crystal 0.72Pb(Mg_(1/3)Nb_(2/3))O_3-0.28PbTiO_3 (abbreviated as PMN-PT) was used to fabricate high performance ultrasonic phased-array transducer as it exhibited excellent piezoelectric properties. In this paper, we focus on the design and fabrication of a low-loss and wide-band transducer for medical imaging applications. A KLM model based simulation software PiezoCAD was used for acoustic design of the transducer including the front-face matching and backing. The calculated results show that the - 6 dB transducer bandwidth can be improved significantly by using double λ/8 matching layers and hard backing. A 4.0 MHz PMN-PT transducer array (with 16 elements) was fabricated and tested in a pulse-echo arrangement. A -6 dB bandwidth of 110% and two-way insertion loss of -46.5 dB were achieved.