Volumetric metamaterials versus impedance surfaces in scattering applications

Abstract Artificially created media allow employing material parameters as additional valuable degrees of freedom in tailoring electromagnetic scattering. In particular, metamaterials with either negative permeability or permittivity creating deeply subwavelength resonant structures relatively high scattering cross-sections. However, the equivalence principle allows replacing volumetric properly designed curved impedance surfaces, ensuring same properties. Here, we examine this statement from a practical standpoint, considering two structures, having dipolar electric resonance at frequency. The first realization is based on arrays inductively loaded dipoles printed stacked circuit boards (a metamaterial), while second structure utilizes 4-wire spiral spherical surface (surface realization). An intermediate conclusion that implementation tends to outperform counterparts scenario when single involved. case where multiple resonances are overlapping and lossy materials involved, can have an advantage. discussed significant importance field electrically small antennas, superdirective superscatterers, which find use wireless communications radar applications, name just few.