Abstract: Acoustically transmissive cloak is constructed with a combination of two labyrinthine type metasurfaces-phase-modulated metasurface and near-zero refractive index metasurface.The near-zero refractive index metasurface is verified by energy band calculation and equivalent medium theory to have zero refractive index property similar to phonon crystals,so that it can guide the acoustic waves to continue to go around the obstacles in the original direction of the acoustic waves;the phase-modulated metasurface,on the other hand,should have a high transmittance while having the role of phase-modulation to ensure that the acoustic waves can pass through in large quantities.The simulations and calculations show that the acoustic transmission cloak formed by the construction works well.

Key words: transmissive acoustic cloak, generalized Snell's law, metasurface, equivalent medium theory