Array Geometry Optimization for Region-of-Interest Near-Field Beamforming

Microphone array geometry plays a crucial role in array signal processing and beamforming. This paper presents an array geometry optimization approach for near-field beamforming. Considering a continuous region of interest, we aim to maximize the worst-case broadband directivity of the array while ensuring sufficiently high white noise gain. We use a near-field wave propagation analysis to formulate a convex optimization problem and find the optimal linear array topology. We evaluate the performance of the proposed approach for different desired signal directions and distances and compare our results to traditional beamformers. The optimized non-uniform geometry achieves better white noise gain and higher array directivity than standard uniform linear arrays. Furthermore, the proposed method can be used for near- and far-field sources.