Coupled Decorated Membrane Resonators with Large Willis Coupling

We report experimental studies on acoustic scatterers consisting of a pair of coupled decorated membrane resonators that exhibit near extreme contrast in reflection asymmetry and enhanced Willis coupling coefficient with an amplitude of 2.5 and a polarizability cross term of 1.1 x 10(-8) ms(2). The design is based on the theoretical analysis using the Green's function formulism we developed earlier. The line shapes of the real and the imaginary parts of the Willis coefficient clearly show that the Kramers-Kronig relations are satisfied.