Carbon-based radar absorbing materials: A critical review

With the development of radar (Radio Detection and Ranging) systems, the study of materials with the capability to block and reduce the reflected electromagnetic radiation to avoid or confuse detection systems, or to protect sensitive devices and living beings exposed to electromagnetic radiation, has become a topic of great interest. This review describes some concepts of the electromagnetic spectrum, radar systems, frequency bands, and radar applications based on their operating frequency, the radar cross-section, and the mechanisms to reduce it, as well as the microwave absorption theory. Furthermore, different carbon-based materials such as carbon black, carbon fibers, nanotubes, graphene, graphene oxide, reduced graphene oxide, and its composites have been used as electromagnetic absorber materials due to their remarkable intrinsic characteristics as lightweight, flexibility, and suitable electric and magnetic properties, are described. This review also explains the principal mechanisms by which these materials can attenuate the radiation. The review is concluded with a summary of the perspectives and challenges for future investigation of carbon-based materials and his electromagnetic characterization for radar signals absorption, interference protection and human security.