双层PZT相控阵换能器研究

Study on Double Layer PZT Phased Array Transducer

为了提升医用相控阵的图像性能,需要用高灵敏度、高带宽的相控阵换能器。通过双层PZT设计,降低换能器电阻抗,进而改进等效电阻抗匹配。在整体振元宽高比固定的情况下,测试不同厚度组合的静态电容和压电耦合系数,找出最佳的双层PZT厚度组合;制作出等厚度双层PZT相控阵换能器,该换能器比常规单层ZPT换能器在灵敏度提高4.56dB,带宽提高5.23%。等厚双层PZT工艺可有效改善小尺寸振元的电匹配,提升换能器整体性能。

In order to improve the image performance of medical phased array,a phased array transducer with high sensitivity and high bandwidth is needed.In this paper,through the design of double-layer PZT,the electrical impedance of the transducer is reduced,and then the equivalent electrical impedance matching is improved.The static capacitance and mechanical coupling coefficient of different thickness combinations are tested to find the best thickness combination of double-layer PZT when the aspect ratio of the whole array element is fixed;A double layer PZT phased array probe with equal thickness has been made.Compared with the conventional single layer ZPT transducer,the transducer has 4.56dB higher sensitivity and 5.23%higher bandwidth.The equal thickness double-layer PZT process can effectively improve the electrical matching of small size vibration elements and improve the overall performance of the transducer.