Hybrid multilayer structures for use as microwave absorbing material

Abstract

The aim of this study is the in situ processing of flexible multilayer radar absorbing structures materials based on polymeric substrates impregnated with polyaniline conducting polymer. There is a growing interest in the development of low density flexible absorber material for applications that require the reduction of the reflectivity of targets with complex shapes and improvement of the ease of transportation of targets. Processed materials having different characteristics were evaluated for the attenuation in the X-band frequency. The results show how the characteristics of the impregnated layers influence the absorbing properties. The anchorage of absorbing centers on the substrate was evaluated and the different structures that were obtained attenuated the incident radiation from 65 to 99%, which indicates that these materials can be used as microwave absorbers.

Radar absorbing materials based on titanium thin film obtained by sputtering technique

“…RAM present innumerous applications, as in equipment electromagnetic shielding employed in automotive and aerospace industries and military technology, as well as in electrical and electronic devices and systems for wireless communication (Biscaro, Rezende and Faez, 2008;Bregar, 2004;Folgueras and Rezende, 2007;Hashsish, 2002;Nie et al, 2007;Rezende, Silva and Martin, 2000). Considering the complexity of the aeronautical engineering area, technological advances involving RAM depend on the development of materials to attend a wide range of frequencies, in other words, wavelengths varying from m to mm.…”

“…These dielectric dipoles are guided by the applied electric field. The interaction between the dipoles and the electric field leads to the formation of aligned dipoles, according to the applied electric field, enabling the material to store potential electric energy (Folgueras and Rezende, 2007).…”

Dielectric properties of microwave absorbing sheets produced with silicone and polyaniline

“…In general terms, it is possible to describe the interaction of an electromagnetic wave with microwave absorbing materials (RAM's) as a phenomenon where the electromagnetic energy is transformed into thermal energy 1,2 . According to the principle of energy conservation, the electromagnetic wave impinging on a material can be reflected, attenuated or transmitted through the material.…”