Resonant Metasurfaces with a Tangential Impedance

Metasurfaces formed by monopole and dipole resonators are studied theoretically. The Helmholtz or membranes vibrating on the first eigenfrequency; ones spheres springs second eigenfrequency. It is shown that acoustic properties of metasurface built-in can be described an equivalent impedance, which characterizes a normal forcing to surface, whereas this impedance not suitable for resonators, because motion excited tangential surface. For such boundaries, new characteristic named “tangential impedance” proposed. This ratio derivative sound pressure along coordinate boundary velocity boundary. impedance. Reflection absorption coefficients surface with found harmonic plane wave in dependance incidence angle. angular dependences very different metasurfaces.