(a) Schematic of the highly homogeneous ZIM. (b) Simulated effective refractive index and impedance of the highly homogeneous ZIM. (c, d) Simulated and measured near-field distributions over the top surface of the ZIM.
(a) Photograph of the ZIM-based antenna. (b) Simulated far-field directivity pattern of the ZIM-based antenna. (c) Comparison of simulated and measured directivities of ZIM-based antennas and those of dielectric antennas with the calculated directivity limits.