Resonant frequency and bandwidth of metamaterial emitters and absorbers predicted by an RLC circuit model

Metamaterial thermal emitters and absorbers have been widely studied for different geometric patterns by exciting a variety of electromagnetic resonances. A resistor-inductor-capacitor (RLC) circuit model is developed to describe the magnetic resonances (i.e. magnetic polaritons) inside the structures. The RLC circuit model allows the prediction of not only the resonance frequency, but also the full width at half maximum and quality factor for various geometric patterns. The parameters predicted by the RLC model are compared with the finite-difference time-domain simulation. The magnetic field distribution and the power dissipation density profile are also used to justify the RLC circuit model. The geometric effects on the resonance characteristics are elucidated in the wire (or strip), cross, and square patterned metamaterial in the infrared region. This study will facilitate the design of metamaterial absorbers and emitters based on magnetic polaritons. (C) 2014 Elsevier Ltd. All rights reserved.