Underwater asymmetric acoustic transmission structure using the medium with gradient change of impedance

Hu Bo^{1, 2}, Shi Jie^{1, 2, †,}, Shi Sheng-Guo^{1, 2}, Sun Yu^{1, 2}, Zhu Zhong-Rui^{1, 2}

(a) Typical gradient profiles of acoustic impedance for three cases: Z_max = 6.4 × 10⁶ kg/(s·m²), 1.1 × 10⁷ kg/(s·m²), and 1.7 × 10⁷ kg/(s·m²). The solid line, dashed line, and dotted line refer to the three cases (from bottom to top), respectively. (b) Comparison of rectifying ratio among the three cases (from bottom to top).