Fig. 4
From: Broadband sound barriers with bianisotropic metasurfaces

Measured sound suppression level. a Measured suppression level compared against the suppression levels expected for amplifiers having impulse response phase gradients of 45°(1000 Hz)−1 and 15°(1000 Hz)−1. b Amplitude and c phase of metasurface bianisotropic relative response pb/pc measured at point A in Fig. 2a and compared against measured amplifier impulse response g