Implementation of Phase Mode Beamforming Using Two Proposed Spherical Arrays

Spherical harmonic array processing, also known as phase mode spherical sensor array processing, has been recently studied for different communication purposes. The spherical array arrangement presents desired three-dimensional symmetry, while the phase modes provide frequency-independent spatial processing. This paper proposes two novel sensor arrangements for spherical array which have been compared with the three sensor arrangements most used in spherical array beamforming. It has been proven that these proposed arrays achieve high directivity and more symmetrical beampatterns compared to the other arrangements. The phase mode beamformer with the element space beamformer has also been analyzed in an acoustic field. Furthermore, the phase mode beamformer has been compared when using the proposed sensor arrangements where different simulations show that the phase mode beamformer, at low frequencies, suffers of a huge reduction in array gain compared to that of the element space beamformer.