Comparative study of experimental and numerical behaviors of microwave absorbers based on ultrathin Al and Cu films

The study of radar absorbing materials increasingly thin, lightweight and flexible has gained growing importance in recent years. In military area these characteristics allow the reduction of weight and volume of platforms, and in civilian sector these materials stimulate innovative projects of electronic and microwave devices. The present work was devoted to studying ultrathin films of Al (20–80 nm) and Cu (10–100 nm) deposited on poly(ethylene terephthalate) (PET) substrate by magnetron sputtering technique. The electrical conductivity values of the films were determined by 4 probes method, the S parameters (S11 and S12) were obtained by transmission line using a X-band waveguide and the skin depth calculated. The results show the dependence of the electrical conductivity with the thickness for both films. The experimental values of microwave attenuation were compared with calculated values based on the equivalent electric circuit theory. This comparison shows a good adjustment and confirms the use of electrical conductivity measurements to predict the microwave absorption behavior of ultrathin films. •This article focuses on recent progresses in ultrathin films aiming microwave absorption.•Nanometric films of Al and Cu deposited on poly(ethylene terephthalate) substrate were produced.•Electrical conductivity (4-probes) and S-parameters (S11 and S12) of nanofilms were measured.•Calculated microwave attenuations were obtained based on the equivalent electric circuit theory.•A good fit between experimental and predictions data of microwave absorption was observed.