Power and ${\rm Q}$ of a Horizontal Dipole Over a Metamaterial Coated Conducting Surface

The radiation properties of an electrically small antenna attached to an infinite conducting ground plane covered by a thin sheet of a metamaterial medium are considered. Using analytical field expressions, the radiation of an electric point dipole with arbitrary constitutive parameters of the material coating is studied. Attention is paid especially to permittivity values close to zero. Finite element simulations are employed to confirm the radiation enhancement and low quality factor $Q$ characteristic of a zero-index coating as compared with regular “air-filling.” The $Q$ is evaluated partly through integration of the energy of the FEM-simulated fields within the antenna region and partly from the nonradiating component of the multipole fields outside the antenna region. Additionally, the influence of surface wave power is analyzed through simulations.