Practical guidelines for the design and implementation of microwave absorber using FSS-frequency selective surfaces

The aim of this work is to provide practical guidelines for the design of microwave absorbers using the theory of FSS-frequency selective surfaces. The design guidelines presented here use simplified modeling to achieve numerical dimensioning which results on the designed absorbers with performance very close to the desired attenuation and bandwidth. The method, which is valid up to the frequency where high propagating Floquet mode occurs, is based on a circuital approach and takes into account the response of the FSS elements which can be represented as either series or parallel LC circuits. To provide absorption on the desired frequency the model uses the natural resonance of the HIS-high impedance surface (occurred at the parallel connection between lossy FSS impedance and the grounded dielectric slab impedance).