Beamforming Based on Joint Optimization for Array Interpolation

Aiming at the inherently problems that interpolated transformation technique can not work effectively over a large transformation area, and the sidelobe level is high during beamforming. In this paper, we propose a new algorithm by designing the weight of interpolated array to jointly optimize sidelobe level and transforming error. The key feature of this algorithm is that in the case of minimizing the error of output signal power which is caused by transforming error, the sum of the sidelobe power is constrained to minimum by the angle weighting function. Numerical simulations prove the validity of this new algorithm. In comparing with the existing algorithms, this algorithm can achieve low sidelobe beamforming in a large transformation area, and it overcomes high current taper, mainlobe expansion, and inability to use the window function to suppress sidelobe in interpolated array. Besides, it has good reception and suppression effects for the spatial wave signals from the mainlobe and the sidelobe, respectively.