Abstract-Concentric ring antenna arrays with the ability to produce dual pattern have many applications in communications and radar engineering. In this paper, we represent a new method for design of an optimized reconfigurable concentric ring array with dual pattern of desired specifications. Here, our goal is to find a suitable common element excitation amplitude distribution and two different element excitation phase distributions for two desired radiation patterns. For this purpose, we have proposed a novel objective function which is completely different from the traditional objective functions usually used in antenna design problems. For the optimization procedure, we have developed a modified Differential Evolution (DE) algorithm, denoted as DE rBM 2SX, which employs new kinds of crossover and mutation operators to overcome some drawbacks of the classical DE on single-objective fitness landscapes. We consider three types of dual pattern -pencil beam+pencil beam, pencil beam+flat-top beam, flat-top beam+flat-top beam. The simulation results obtained by applying our proposed method clearly indicate that our method is very convenient to obtain radiation patterns of desired specifications. We compare results of the modified DE algorithm with those of another state-of-the-art improved variant of DE, called JADE and a state-ofthe-art variant of the Particle Swarm Optimization (PSO) algorithm called Comprehensive Learning Particle Swarm Optimizer (CLPSO). Such comparisons reflect that the proposed algorithm is more efficient than JADE or CLPSO in finding optimum configuration of the dual pattern concentric ring array antenna.