Discussion of a leaky-wave metamaterial design and the effects of membrane thickness on the dispersion direction

Acoustic leaky-wave metamaterials (LWM) are commonly used in beam-steering situations such as radars, imaging, and other such frequency scanning applications. LWM are particularly useful metamaterials due to their broad scanning range allowing for more use from a single frequency sweep. This is accomplished with a relatively simple structure of repeated cells in a linear array. Among current methods to model and design acoustic LWM are notably high fidelity models such as finite element analysis and low fidelity models such as the acoustic transmission-line equations. In this study, a frequency domain model is developed using 4-pole methods and lumped elements. This model is used to explore rapid evaluations of different tuning options in the thin plates separating the unit cells of the structure. In future studies, this model will be further developed to create a mid-fidelity model of an acoustic LWM using modal analysis.