Three-dimensional beamforming performance of spherical microphones array

In order to analyze the effect of spherical array structure parameters on the three-dimensional beamforming noise source identification performance, based on the Delay-and-Sum beamforming theory, the mainlobe width and the maximum sidelobe level were simulated and analyzed using varied diameters. Results indicated that the larger the diameter, the better the spatial resolution became. However, a larger diameter caused a weaker sibelobe inhibitory ability. Furthermore, the radial profile of array pattern and the maximum sidelobe level for five typical spherical arrays were studied. Results showed that the uniformly distributed microphones array had the best performance. When the wavenumber was 50-100 rad/m, the maximum sidelobe was about -12 dB, and when the wavenumber was up to 220 rad/m, the maximum sidelobe was still less than -6 dB. Therefore, increasing the uniformity and density of the microphones distribution can significantly improve the beamforming performance.