宽频可调声非对称传输器件设计

Narrow bandwidth and complicated structure are the key drawbacks for existing asymmetric acoustic transmission devices. A unidirectional acoustic transmission device composed of bended tubes and two different kinds of acoustic metasurfaces is proposed in this paper. One-way acoustic transmission is realized in the bandwidth from 6000 Hz to 8500 Hz. The properties of the unidirectional acoustic transmission are implemented by the anomalous reflection and refraction with acoustic metasurfaces. The relatively high transmission efficiency of the one-way device is realized by the impedance matching between the inert gases filled in the acoustic metasurface elements and air as the background medium. A more efficient one-way transmission design is obtained by adjusting the elbow angle. Additionally, two-way acoustic insulation can come true by rotating the refractive acoustic metasurface automatically. Appropriate strategies are generated to satisfy different needs for two-way insulation with acoustic metasurfaces. Our work provides a simple method of designing a broadband unidirectional acoustic transmission device and has potential applications in many fields such as noise control, medical ultrasound and imaging.