Educational open source kit for the evaluation of acoustic leaky wave antennas with metamaterialsa

There is a growing interest in the field of acoustic metamaterials. These materials use periodic structures to exhibit properties not usually found in nature, such as negative mass or negative compressibility. The physics supporting these devices might seem counterintuitive at first, necessitating additional educational resources in this area. A leaky wave antenna (LWA) is a good example of a practical device that can be implemented as a standard material and a metamaterial. As the latter, the device extends its operational range, linking concepts related to both versions. This work presents an experimental open source kit designed for teaching the basic notions, including a computational routine for testing its analytical performance. The kit shown in this work has interchangeable units to experiment with several configurations (slit, axisymmetric, periodic hole, and membrane based metamaterial) and parameters of the antenna's design. The kit provides an opportunity to get hands-on experience on the real-life performance of LWAs, thanks to the use of low-cost materials, minimal equipment, and the practical nature of the antenna.