Dolph-Chebyshev beampattern design for spherical arrays

Spherical arrays with array processing based on spherical harmonics have been recently studied for a wide range of applications that require three-dimensional beamforming. In this correspondence, a Dolph-Chebychev beampattern design, widely used in array processing due to the direct control over main-lobe width and maximum sidelobe level, is developed for spherical arrays within the spherical harmonics framework. We show that due to the similarity between the Legendre polynomials that define the spherical array beampattern and the Chebyshev polynomials that define the desired Dolph-Chebyshev beampattern, spherical array weights can be computed directly and accurately given desired main-lobe width or sidelobe level.