Extending the Bandwidth of Electric Ring Resonator Metamaterial Absorber

An efficient method is proposed to extend the bandwidth of a metamaterial absorber with multi-resonance structure. The basic unit cell of a metamaterial absorber consists of the electric ring resonator, dielectric substrate (FR-4) and split-wire. By assembling five sandwiched structures with different geometric dimensions into a unit cell, we obtain the superposition of five different absorption peaks. Finally, the bandwidth of metamaterial absorption is extended and the full width at half maximum is up to 1.3 GHz. The simulated and experimental results are consistent.