Grating-Lobe Suppression of Non-uniform Large-Element-Spacing Antenna Arrays

Large-element-spacing (LES) arrays provide cost-effectiveness and structural simplicity. However, they experience the drawback of excessive grating lobes. In this study, we tackle the problem by introducing a metasurface lens positioned above a non-uniform LES array. The purpose is to manipulate and correct the phase characteristics of the near fields produced by the array; in doing so, the grating lobes are reduced or eliminated. Theoretical analysis and simulations of an example design are conducted. The results show that this approach can not only mitigate the grating lobes from the non-uniform LES array but also increase the antenna gain and aperture efficiency.