Analyses of pattern function of the DBF in non-uniform subarrays and a modified weighting method

The characteristics of pattern function of DBF composed of subarrays are analysed and a condition for the formation of grating lobes is given. For the design of DBF, some conventional weighting methods, f.i., the Hamming weighting, the cosine-squared weighting and the cosine-cubed weighting, are only suitable for uniform array directly composed of array elements. In this contribution we modify these methods to let them be self-adaptable, which is fit for a variety of arrays including the DBF in non-uniform subarrays. The principle of this new method is to modify weighted coefficients according to the relative positions of subarrays in the array. Both of the analyses and the computer simulation results demonstrate that this method is rather effective.