Spherical–omnidirectional acoustic source has become a powerful tool to provide a near-ideal omnidirectional beam pattern for acoustic tests and communications. Current spherical–omnidirectional acoustic sources do not combine an omnidirectional beam pattern with a high transmitting voltage response (TVR) in the frequency range of above 200 kHz. This work presents the design, fabrication, and measurements of a high-frequency spherical–omnidirectional transducer that can provide a near-ideal omnidirectional beam pattern and a high TVR. The active element of the transducer consists of six identical square coupons with spherical curvature 1–3 piezoelectric composites operating in thickness mode. Electroacoustic responses of the fabricated transducer in water were measured. The measured resonance frequency of the transducer was 280 kHz. The maximum TVR was 161.3 dB re ${1}~\mu $ Pa/V@1 m. The horizontal and vertical beamwidths of the transducer were 360° and 346°, respectively. Measurements show that the spherical piezoelectric composite transducer has a favorable spherical–omnidirectional behavior and a high TVR at high frequency. These results demonstrate that the spherical piezoelectric composite transducer is potentially a strong candidate for a high-frequency underwater acoustic source that requires an omnidirectional response.

中文翻译：

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高频水下声学的球形全向压电复合换能器

球形全向声源已经成为为声学测试和通信提供近乎理想的全向波束方向图的强大工具。当前的球形全向声源没有在200 kHz以上的频率范围内将全向波束方向图与高发射电压响应（TVR）结合在一起。这项工作介绍了高频球形全向换能器的设计，制造和测量，该换能器可以提供近乎理想的全向波束方向图和高TVR。换能器的有源元件由六个相同的方形试样组成，这些试样具有在厚度模式下工作的球形曲率1-3压电复合材料。测量了所制造的换能器在水中的电声响应。测得的换能器共振频率为280 kHz。 $ {1}〜\ mu $ Pa / V @ 1 m。换能器的水平和垂直波束宽度分别为360°和346°。测量表明，球形压电复合换能器具有良好的球形-全向性能，并且在高频下具有较高的TVR。这些结果表明，球形压电复合换能器可能是要求全向响应的高频水下声源的强大候选者。