Authors:
Ratiba Benzerga | Univ Rennes, CNRS, IETR-UMR 6164, F-35000 Rennes, France | France
Hanadi Breiss | Univ Rennes, CNRS, IETR-UMR 6164, F-35000 Rennes, France | France
Aicha El Assal | Univ Rennes, CNRS, IETR-UMR 6164, F-35000 Rennes, France | France
Ali Harmouch | College of Engineering, Ahlia University, Manama, Bahrain | Bahrain
Akil Jrad | LaSTRe, Université Libanaise de Tripoli, Liban | Lebanon
Ala Sharaiha | Univ Rennes, CNRS, IETR-UMR 6164, F-35000 Rennes, France | France
Today, electromagnetic absorbers for a microwave application are the subject of several studies with the aim of proposing new absorbers that have an increasingly larger operating bandwidth with an increasingly smaller thickness.
In this work, we propose a new flexible absorber material based on silicone foam filled with carbon fibers, and presented in the form of periodic structures. The originality of this proposal lies in the combination of two simple manufacturing concepts: on the one hand, a very simple method of preparing the flexible silicone foam, and on the other hand, the simple periodic structuring of the absorber.
This new absorber can be considered as an organic metamaterial; which allows to overcome the metallization used to make standard metamaterial absorbers. In fact, this metallization is often susceptible to corrosion and represents a limitation for the use of metamaterial. Moreover, our proposed absorber makes it possible to combine the absorption due to the resonant frequencies of the metamaterial, and the dielectric losses of the composite, to obtain a broadband absorber. To do so, a silicone foam, with a density of 0.33 g.cm-3, loaded with 2% of carbon fibers of 12 mm length, was used. After a parametric study of the absorber, using the dielectric properties of the composite, the proposed absorber structure is composed of a continuous layer of the composite with a thickness of 6 mm, associated with parallelepipedal structures (14 x 14 x 10 mm3) deposited on it; the total thickness of the absorber is 16 mm. The simulation of this absorber predicts a reflection coefficient lower than – 10 dB between 4 and 18 GHz, which is confirmed by the measurement, in the anechoic chamber, of the produced absorber. These results confirm the potential of the proposed material and structure for the achievement of a flexible, lightweight and broadband, organic metamaterial absorber.