中文摘要：

设计一种超声谐振器，旨在解决超声传感器远程测距中因超声波能量分散和衰减过快导致的回波信号难以识别问题。首先，根据声学理论分析了超声谐振器可以通过改善阻抗匹配提高其辐射效率；再利用Bessel函数分析了超声谐振器影响声源指向性的重要设计参数，通过改变声源频率、谐振器开口面积等设计参数可以使指向性尖锐，能量更集中。Matlab仿真计算与相应的实验均证明了理论分析的正确性和优化谐振器设计参数对提高超声探测距离的有效性与可控性。

英文摘要：

Design a kind of ultrasonic resonator, in order to solve the problem of difficulty of echo signals identification caused by energy dispersive and fast attenuation in ultrasonic sensor long-distance ranging. Firstly, according to theory of acoustics analyze ultrasonic resonator can increase radiant efficiency by improving impedance match. Then, use Bessel function, analyze important design parameters,which affect directivity of sound source ,by changing design parameters such as sound source frequency, opening area of resonator, make the directivity sharp and energy centralized. Using Matlab simulative computation and experimental show that the theoretical analysis is correct, and the effectiveness and controllability of optimum design parameters of resonator for improving the ultrasonic detecting distance.