An Ultra-thin Triple-band Metamaterial Absorber with Equivalent Circuit Analysis

A compact ultra-thin triple-band metamaterial absorber with polarization insensitiveness and wide-angle stability is presented in this paper. The unit cell of the absorber consists of a Jerusalem cross and a concentric circular ring imprinted on a dielectric substrate backed with a metal ground plane. Simulated results exhibit that the proposed absorber has three discrete absorption peaks at 4.4, 6.05, and 13.9 GHz with excellent absorption rates over 0.95. The current distribution and equivalent circuit analysis are investigated to analyze the near-unity absorption mechanism. The structure is then fabricated and experimentally characterized. The measured absorption response shows a good agreement with the simulated and calculated results.