Application of weighting methods adapting to array structure for design of DBF in subarray [radar beamforming]

The characteristics of the pattern function of DBF (digital beamforming), composed of subarrays, are analysed and a condition for the formation of grating lobes is given. Conventional weighting methods to suppress sidelobes, i.e., the Hamming weighting, the cosine-squared weighting and the cosine-cubed weighting, are only suitable for uniform arrays directly composed of array elements. In this contribution, we modify these methods, namely, introduce modified weighted coefficients according to the relative positions of subarrays in the array to let them be suitable for a variety of arrays including the DBF in non-uniform subarrays. These weighting methods are adaptable for array structures. Both of the analyses and the simulation results demonstrate that these methods are fairly effective.