Equivalent Circuit Modeling of Frequency-Selective Surfaces Based on Nanostructured Transparent Thin Films

An equivalent circuit is proposed to model frequency selective surfaces (FSSs) made of optically transparent metal patches. The field penetration through a unit cell of a simple FSS is modeled circuitally by a shunt admittance composed by inductance and capacitance, while the losses in the parts covered by metal thin film are modeled by resistances. The circuit results are validated by full-wave numerical simulations for different test configurations. The circuit model permits fast simulations adequate for FSS design.