针对空气耦合超声换能器存在换能器与空气介质阻抗失配，易造成电声转换效率低等问题，该文提出了一种采用空心酚醛树脂微球与环氧树脂基体研制的声匹配层，并对匹配层的声学特性进行测试与分析。测试结果表明，与空心玻璃微球匹配层相比，空心酚醛树脂微球匹配层具有声速更低及插入损耗更大的特点。基于此，该文研制了一种空气耦合超声换能器，对两只经匹配后的换能器进行测试，分析了接收信号的时域及频域特征，并与空心玻璃微球匹配层换能器进行性能对比。结果表明，与空心玻璃微球匹配层相比，采用空心酚醛树脂微球匹配层可减小换能器带内起伏，使换能器的-6 dB带宽扩展2倍以上，并在时域上减小接收信号的拖尾。

The use of air-coupled ultrasonic transducers and the air medium presents issues with impedance mismatching, which can significantly reduce electro-acoustic conversion efficiency. To address this problem, this article introduces a novel acoustic matching layer made of hollow phenolic resin microspheres embedded in an epoxy resin matrix. The acoustic characteristics of this matching layer were thoroughly tested and analyzed. The test results indicate that the hollow phenolic resin microsphere matching layer demonstrates lower sound velocity and higher insertion loss compared to the hollow glass microsphere matching layer. Building upon these findings, an air-coupled ultrasonic transducer was developed. Two matched transducers were subjected to testing, and both the time-domain and frequency-domain characteristics of the received signals were analyzed, and compared their performance with the hollow glass microsphere matched layer transducers. The results revealed that compared with the hollow glass microsphere matching layer, the hollow phenolic resin microsphere matching layer can reduce the in-band undulation of the transducer, expand the -6 dB bandwidth of the transducer by more than 2 times, and reduce the tailing of the received signal in the time domain.