Modeling of metamaterial absorber by equivalent resonant circuit

The resonant absorption in an ultrathin metamaterial is studied theoretically. We present a simple physical model describing this phenomenon based on equivalent resonant circuits. We discuss the role of radiative and dissipative damping of resonant mode supported by the metamaterial in the formation of absorption spectra. We show that the results of rigorous calculations of Maxwell equations can be fully retrieved with this simple model. This model allows us to explain the total absorption effect observed in the system on a common physical ground by referring it to the impedance matching condition at the resonance.