Performance analysis of pixelated antennas employing shifted cross‐shaped elements

Abstract

AbstractThis article presents a detailed analysis of pixelated antennas employing shifted cross‐shaped elements optimised by evolutionary algorithms. Although, the size and number of the involved pixels, as well as the overall antenna size strongly influence performance of such antennas, detailed investigations on the interplay of geometrical considerations and their influence on parameters such as gain are missing from literature. Thus, the influence of various geometrical parameters on the performance of pixelated antennas for the first time, resulting in valuable design considerations is presented in this study. A maximum cross size could be found, for which an optimisation is viable. Based on this, a dataset consisting of 400 pixelated antennas was created, for different pixel‐ and antenna sizes and investigated certain parameters such as bandwidth and antenna gain. Most notably, a directly proportional dependence from the pixel‐on the antenna size for the optimisation of electrically large antennas was found. For small antennas, this dependency begins to deviate, leading to the fact that smaller pixels are needed to successfully optimise an antenna. Furthermore, the authors find that multi‐objective optimisation is a necessity to optimise matched antennas with a defined bandwidth and gain. The antenna gain shows a dependency on the cross size for electrically small antennas. From these results, design considerations for pixelated antennas can be derived. In addition to the extensive simulations, the dataset was verified in laboratory measurements.