An Focusing Method in an High Acoustic Impedance Materials Using Arrayed Sources Distributed on the Surface of the Sample

(1)利用传输线耦合器聚焦高阻抗材料中的超声波波束的研究：提出了一种将超声波波束聚焦到固体材料中的方法。使用固体表面上的分布式点源。使用超声波传输线的尖端形成点源。进行了模拟研究和实验研究。该方法的主要优点是空间分辨率与杆尖直径有关，不受瑞利准则的限制。(2)提出了一种测量复声阻抗的方法：提出了一种用熔融石英棒作为传输线测量小样本复声阻抗的方法。该方法具有简单、准确的特点。实验结果表明，该方法测量阻抗的精度小于1%。

(1)A Study for Focusing Ulitrasonic Beam in a High Impedance Materials using Transmission Line Coupler :A method for focusing an ultrasonic beam within a solid material is presented. Distributed point sources on the surface of the solid are used. The point souces are formed using the tip of an ultrasonic transmission line. A simulation study as well as experimental study was conducted. The main advantage of the method is that the spatial resolution is related to the diameter of the tip of the rod and is not limited by Rayleigh criterion.(2) A Method for Measuring Complex Acoustic Impedance :A Method for measuring complex acoustic impedance in small sample using a fused quarts rod as a transmission line is develope. The method features its simplicity and accuracy. The experimental results show that the impedance can be measured with an accuracy less than 1%.