Pattern synthesis of time-modulated conformal arrays by an improved differential evolution algorithm

Abstract

In this article, an improved differential evolution algorithm IDE based on two different colonies is proposed and applied to time-modulated conformal arrays syntheses. The whole population of IDE is divided into two parts. The one part searches the solution globally while the other searches the neighborhood of the solution provided by the previous one. Benchmark functions are provided to testify IDE. Furthermore, IDE is applied to synthetize sum-difference patterns with a 1 × 16 elements time-modulated circular array and low sidelobe level SLL patterns with an 8 × 12 elements time-modulated cone array. After optimization, the sideband level SBL of the circular array at the first sideband frequency is -1.00 dB. The SLL and SBL at the first sideband frequency of the cone array are lower than -30.00 and -20.00 dB, respectively. Experiment results verify the superior performance of IDE. Moreover, to accelerate the computation speed, graphics processing unit parallel computing technique is introduced into pattern synthesis and the acceleration ratios of more than 23 times can be achieved. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:697-705, 2014.