Analysis and a novel design of the beamspace broadband adaptive array

An analysis of the broadband beamspace adaptive array is provided. There are two conditions imposed on the array. First, the individual beams should have a good frequency invariant property. Second, they should be linearly independent. However, these two conditions are not independent and it is shown that there is a trade-off between them. To improve the interference cancellation capability of the array, we may need to sacrifice the frequency invariant property of the beams to some degree for more linearly independent beams. A DFT-modulated design method is also proposed, where the beam directions are uniformly distributed over the spatial domain and the linear independence of the beams is guaranteed inherently. Simulation results verified our analysis and the proposed method.