DESIGN OF THIN MICROWAVE ABSORBERS USING LOSSY FREQUENCY SELECTIVE SURFACES

An alternative procedure for the optimal design of both narrow and wide band electromagnetic absorbers is presented. The method, based on equivalent-circuit model in conjunction with the full-wave simulation, is used for computing lumped parameters of the frequency selective surface (FSS) elements. Thus, the procedure is applied to high-impedance surfaces (HIS) to derivate the desired absorbers. The design presented here use simplified modeling to achieve numerical dimensioning of the FSS which results on the designed absorbers with performance very close to the desired attenuation and bandwidth. The resulting absorbers are implemented by placing lossy FSS over a dielectric layer backed by a metal ground plane. The experimental results show good agreements with theoretical results and the validity of the modeling method for the proposed structure. Characteristic attenuation for fabricated narrow band absorber show almost 20-dB in 5.5 GHz. The attenuation bandwidth below -10 dB of the wideband absorber can reach 10-16 GHz with 3 mm thick only. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:928-933, 2015