Experimental study of an tunable acoustic phase-shifter

The paper presents the results of a numerical and experimental study of an acoustic phase-shifter based on a chain of rectangular Helmholtz resonators. Phase regulation of the transmitted acoustic wave is made by simultaneously changing the resonators volumes with the stepper motor. As a result of the experiment it was found that the developed acoustic phase-shifter allows to manipulate the wave phase within the range of 0 – 2$\pi$ in the frequency range of 2000 – 2500 Hz. The transmittance factor is not less than 0.7. The phase-shifter can be used as a unit cell of tunable acoustic metasurface.