Directive Emission Obtained by Mu and Epsilon-Near-Zero Metamaterials

In this work, we use Mu and Epsilon-Near-Zero (MENZ) metamaterials to realize the substrates that can modify the emission of an embedded line source. Simulation results show that the cylindrical waves emitted from the line source can be perfectly converted to plane wave through the MENZ metamaterial slab with planar exit face. Hence the line source together with the metamaterial slab constructs a high directive slab antenna. The directive radiation pattern of the MENZ metamaterial-assisted slab antenna is independent on the thickness of the slab, the position of the line source, and the shape of the entrance face of the slab, but the slab with grooved entrance side will result in stronger far-field intensity. We also show that the MENZ metamaterials can be applied to the design of antenna array. Moreover, compared with the high directive slab antenna obtained by coordinate transformation approach, the MENZ metamaterial-assisted antenna is more preferable.