Broadband impedance-matched near-zero-index metamaterials for a wide scanning phased array antenna design

We present broadband near-zero-index metamaterials composed of dielectric resonators and metallic rods, whose permittivity ε and permeability μ are near-zero simultaneously. It is notable that the values of permittivity ε are equal to those of permeability μ over a broadband frequency range of 8.45 GHz to 10.5 GHz, indicating the impedances of the proposed near-zero-index metamaterials match vacuum in this broadband. The broadband near-zero-index metamaterials for manipulating radiation sources are analyzed. We also demonstrate numerically that such near-zero-index metamaterials can offer a unique grating condition in a phased array antenna, with the beam scanning angle range beyond the critical angle limit of the grating lobe.