Multi-beam generations at pre-designed directions based on anisotropic zero-index metamaterials

We show that anisotropic zero-index metamaterials (AZIMs) can be utilized to realize single- and multiple-beam generations in the pre-designed directions. It has been shown that a high-gain beam will be generated when a line source is located in an AZIM, directing to the AZIM principle-axis direction. By rotating the principle axis to an arbitrary angle, the beam direction is adjusted correspondingly to that angle. Therefore, multi-beams are generated at the desired directions by designing differently oriented AZIMs. An experiment is carried out to validate this property, which shows good agreement to the theoretical analysis.