Dual-Fano resonances based on all-dielectric toroidal metamaterial

Abstract Dual-Fano resonances have been proposed with all-dielectric toroidal metamaterials in the microwave frequency. The presented structure consists of high permittivity rectangular bars of equal spacing. Two transparency peaks derived from the strong toroidal dipole with two modes can reach 0.92 and 0.9 at 10.51 GHz and 16.27 GHz, respectively. The excitation of these resonances could be explained by near-field distribution and multipoles scattered power. The trend of experimental results is virtually uniform with that of theoretical analysis and simulated curves. Such a compact all-dielectric structure may have important implications in many fields, such as ultra-sensitive sensors, stealth transmission, and so on.