Abstract
The concept and applications of composite right/left-handed (CRLH) metamaterials are overviewed.
First, based on equivalent circuit models, the composite nature of left- and right-handedness of CRLH
metamaterials are shown theoretically. Then, the concept of balanced CRLH metamaterial is presented.
It is shown that the CRLH metamaterials possess three unusual phenomena under the balanced condition,
i.e., 1) vanishing the bandgap between the left and right-handed bands, 2) a Dirac cone with linear
dispersion characteristics at the Γ-point, and 3) a continuous Bloch impedance at the Γ-point. Finally,
typical microwave applications of CRLH metamaterials of wide range beam scanning leaky-wave
antennas, zeroth order resonators, and absorbing Dirac cone metamaterials are introduced.
