Fig. 2: Design of the acoustic circulator.
From: Janus acoustic metascreen with nonreciprocal and reconfigurable phase modulations
a Schematic diagram of the single acoustic circulator consisting of cavity, rotor, cover, and rotating rod as marked in the figure. b The cross sectional view of the circular. c The physical model for the numerical simulation of the circulator. The three ports (ports 1–3) are marked by blue arrows. d The simulated transmissions from port 1 to port 2 for the single circulator with different rotation speeds n = ±720 rpm, n = ±480 rpm, n = ±240 rpm, and n = 0 rpm. The maximum and minimum of transmission appear at 6430 Hz with n = +720 rpm and n = −720 rpm, respectively. e The simulated transmission as function of the rotation speed. At the optimized rotation speed n = 720 rpm, the transmission is of about 0.97. f The simulated (Sim., n = 720 rpm) and experimental (Exp., n = 720 rpm) transmissions around 6430 Hz. g The experimental transmission as function as the rotation speed. The maximum transmission is reached at n = 720 rpm, corresponding to the motor voltage of U = 9 V.
