Numerical study of an acoustic leaky wave antenna

Acoustic leaky wave antennas (LWAs), introduced as frequency scanning devices, have been studied in recent years for Direction of Arrival (DOA) and highly directional frequency-selective transmission due to their advantages over multi element arrays such as compactness and low-power requirements. This work presents a numerical study through Finite Element Method (FEM) that solves the Helmholtz Equation using code based on the open-source FEniCS Project. The model under study is a one-dimensional acoustic LWA with axysimetric open channels that performs as a transmitter from broadside to endfire directions. We describe the numerical method applied and validate the code with a lumped-element analysis approximation over the frequency range of interest, showing good agreement in the results. Visualization of different aspects of the LWA like the dispersion relation and scattering parameters, among others are presented. Discussion also focus on the scripting possibilities for automation and inspection of large parameter spaces. This approach proves useful when considering termination effects like end-correction or when exploring new designs with irregular geometries that could provide better performing, but where theoretical modeling turns complicated. [Work supported by UNAM-PAPIIT TA100620.]