Low‐cross‐polarisation synthesis of conformal antenna arrays using a balanced dynamic differential evolution algorithm

Abstract

Conformal antenna arrays often have many elements with different radiation patterns and much cross-polarisation. Those factors make synthesising radiation patterns a difficult problem. In this study, the authors propose a balanced dynamic differential evolution (BDDE) algorithm to suppress the cross-polarisation in conformal arrays. To increase the probability of the inferior group participating in the mutant, a suboptimal individual is adopted in the mutant operation. Parameters are dynamically updated to accelerate the convergence speed. We adjust the cross-rate to its maximal value every few generations to increase the diversity in the population. Two conformal arrays are modelled to verify the ability of BDDE to synthesise the radiation pattern and polarisation simultaneously. To avoid increasing the number of unknowns caused by dual-feed antennas, circular polarised patch antennas with one feed are used to compose the conformal arrays. Embedded element patterns are used in the synthesis to take into account the influence of mutual coupling between the elements and their environment. We compare BDDE with other popular DE algorithms, and simulation results show that the proposed algorithm achieves lower sidelobe levels and cross-polarisation reliably and efficiently.