Reducing mechanical cross-coupling in phased array transducers using acoustic metamaterial as backing

Phased array transducers are widely used for acoustic imaging and surround sensing applications. A major design challenge is the achievement of low mechanical cross-coupling between the single transducer elements. Cross-coupling induces a loss of imaging resolution. In this work, the mechanical cross-coupling between electro-acoustic transducers is investigated for a basic model. For this issue, the operating frequency is set to a low kHz range which is typical for surround sensing applications. The dimensions of the backing are small with regard to the wavelength which leads to wave reflections on the backing edges. This is different to other researches. It is shown in numerical simulation that a reduction in mechanical cross-coupling can be achieved by using acoustic metamaterial as backing. The effect of using acoustic metamaterial has been validated experimentally. The measurement results show good accordance with the simulation.