A novel method for the design of two-dimensional (2-D) and three-dimensional (3-D) arrays with frequency invariant beam patterns is proposed. By suitable substitutions, the beam pattern of a 2-D or 3-D arrays can be regarded as the 3-D or 4-D Fourier transform of its spatial and temporal parameters. Since frequency invariance can be easily imposed in the Fourier domain, a simple design method is derived. Design examples for the 2-D case are provided.
['Wei Liu', 'Stephan Weiss', 'John G. McWhirter', 'Ian K. Proudler']
Frequency invariant beamforming for two-dimensional and three-dimensional arrays