Fishnets Metamaterial Gradient-Index Lens for Phase Correction of a Horn-Antenna at 60 GHz

In this paper, a fishnet metamaterial based gradient-index lens for phase correction of a 60 GHz horn antenna is presented. The single unit cell layer, which constitutes the lens, is fabricated from an aluminum metalization on industry-standard polymer film, which makes the assembly lightweight and cost-efficient. First, a suitable range of unit cell geometries is determined and examined for its transmission phase and magnitude characteristics through full-wave simulation. After determining the near-field phase distribution of the horn antenna, a phase-correcting lens design is constructed from the unit cell results, with the aim of narrowing the antenna's mainlobe. Far-field measurements of fabricated prototypes verify the performance, showing a significant reduction of the half-power beam width and side-lobe level.