Simulated annealing approach for the design of unequally spaced arrays

A synthesis method aimed at designing an array antenna is proposed. Simulated annealing (SA), which is a probabilistic methodology used to solve combinatorial optimization problems, has been utilized to optimize the position and the weighting coefficients of the array elements in order to improve the antenna performance. The sensor position and related weighting coefficients are considered as parameters to be tuned in order to constrain the directivity function (i.e., the beam power pattern) of an antenna to satisfy specific requirements. Conventional beamforming is utilized to compute the beam power pattern having the desired properties, such as a narrow width of the main lobe, and side lobe amplitudes under a certain threshold, etc., taking into account the need to reduce to number of sensors with a small spatial aperture. Several results are presented showing a notable improvement in the antenna performance utilizing the SA approach with respect to those considered in the literature