Polarization-independent multiband double-negative metamaterial through ferrite-based flexible substrate with tunable microwave dielectric properties

Microwave flexible dielectric materials offer a new set of attractive applications for modern devices as well as for metamaterial research and technology. In this article, metamaterials with double-negative characteristics fabricated on a novel flexible dielectric substrate are presented. These novel flexible microwave substrates were prepared from Mg-Zn ferrite powder. The proposed flexible metamaterials offer double-negative (DNG) properties, polarization insensitivity, and a higher effective medium ratio (EMR) for multiple bands of application. The prepared, flexible substrates exhibit performance superior to commercial materials with tunable dielectric properties, and the proposed metamaterial structure enhances the antenna performances as well. The flexible substrates are synthesized from Mg-Zn ferrite having two different molecular compositions of Mg denoted as Mg-40 and Mg-60. The prepared, highly flexible, and lightweight magnesium zinc ferrites of Mg-40 and Mg-60 possess tunable dielectric properties with relative dielectric permittivity of 5.18 and 4.20 and dielectric loss tangents of 0.004 and 0.006, respectively. The double-negative (DNG) metamaterial behavior is observed with the fabricated flexible metamaterials at 2.92 GHz, 4.42 GHz, 7.75 GHz, and 9.84 GHz for Mg-40 and 3.16 GHz, 4.71 GHz, 8.21 GHz, and 10.52 GHz for Mg-60 and validated by using 3D electromagnetic Simulator CST (Computer Simulation Technology) Microwave Studio and ADS (Advanced Design System) software. Therefore, the prepared, flexible metamaterials having improved EMR, polarization insensitivity, and DNG properties on a MgZnFe2O4 substrate are suitable additions to the field of the flexible microwave.