Synthesizing antenna array sidelobe levels and null placements using the Cross Entropy method

This paper describes the synthesis of linear antenna arrays using the cross entropy (CE) method to produce array responses with minimum peak sidelobe levels (SLL) and position nulls at specific angular locations. The CE method is a very simple, yet highly efficient approach to solving complex multi-objective and multi-extremal optimization problems. CE seeks to adaptively estimate an optimal sampling distribution which generates solutions in the neighborhood of the globally optimal solution by minimizing the cross entropy (or Kullback-Leibler divergence) between current best estimates and the overall estimate of the optimal distribution. The performance of CE is comparable to other popular optimization techniques such as the genetic algorithm, simulated annealing and particle swarm optimization.