Figure 2
(a) Schematic of the resonator-based acoustic sensor (top) having three resonant cavities and the acoustic sensor without resonators (bottom, referred to as reference). When measuring the reference sensor, the microphones are inserted into the same positions as those of the resonator sensor for fair comparison. Dashed circles indicate the positions where acoustic pressures are calculated in the simulations. The legends “Exp.” and “Sim.” correspond to the experimental measurements and the FEM simulations. (b) Spectra of acoustic pressures in three cavities of the resonator-based sensor when incident angle is \(\theta_{inc}\) = 40°. Variations of (c) acoustic pressures and (d) phases in three cavities at 900 Hz for different incident angles. (e) Maximized ratio between acoustic pressures in two cavities and (f) phase difference over the range of frequency from 800 to 1300 Hz.
