Synthesizing wide-band sparse arrays by simulated annealing

Although a great amount of work has been done to develop and optimize weighting windows for an array working in narrow-band, one can verify that these windows do not provide optimal results when applied under wide-band conditions. In addition, also the methods of array thinning proposed in the literature have been devised mainly under narrow-band conditions. In this paper, after a proper definition of the wide-band beam pattern, a method is proposed that is aimed at determining the values of the weight coefficients to be assigned to the minimum set of elements of a linear array that generates a beam pattern fulfilling some a priori fixed constraints. This method relies on a stochastic scheme based on the simulated annealing algorithm. Some results showing a notable improvement in array performances (in terms of main lobe width, side lobes level, and number of array elements) with respect to unitary weighting, dense array structures are hereby presented.