Fully Steerable Beamforming for Acoustic Vector Sensor Planar Array With Small Aperture

Conventional differential directivity algorithms are highly dependent on array configuration, especially when designing steerable differential beamformers. To this end, we proposed a method for designing fully steerable directional differential beamformer based on acoustic vector sensor (AVS) with arbitrary planar array. This method addresses the challenges posed by the limited size of small platforms, strict constraints on array configuration, and weak detection capability, thereby enabling fully steerable beamforming detection using small-sized arbitrary planar geometry AVS array (APG-AVSA). The Nth-order differential beamformer is implemented by obtaining individual channel weight vectors, which cause the steering vector to converge to the target beampattern through Jacobi-Anger expansion (JAE). The major advantages of this approach are as follows: 1) a fully steerable differential beamformer design method based on APG-AVSA, which overcomes the limitations of array geometry on the performance of steerable differential beamformer, is proposed and a closed-form solution for Nth-order beamformer is provided, and 2) a theoretical derivation of the first-order white noise gain (WNG) of the proposed algorithm is given, demonstrating the proposed algorithm overcomes the problem of white noise amplification inherent in conventional differential directional algorithms. Finally, the performance of the proposed algorithm was verified through simulation comparisons and external experimental data.