Shell absorbing nanostructure for low radar observable missile

摘要

This research is focused on simulation, manufacturing and measuring of shell radar absorbing structure of missiles. The novelty of the work is the study of a curved radar absorbing structure. The enhancement of electromagnetic wave absorption is obtained by using carbon nanotube filler in different weight ratio with respect to the epoxy-resin adopted in shell manufacturing. The structural resistance is granted by the use of conventional fiberglass. A radar absorbing prototype of an half shell, having the section of 15 cm radius has been built and characterized. The thickness of the shell is around 6.5 mm and is made of two different loaded layers. The measurements of electromagnetic reflection coefficient has been performed for two different incidence angles of 0° and 45°. The reflection coefficient show values down to -18 dB around 3 GHz and -10 dB around 11 GHz for 0° incidence angle, and -6 dB around 3 GHz and -10 dB around 12 GHz for 45° incidence angle. An electromagnetic simulation of a flat structure having the same layering configuration of the shell shows values of reflection coefficient very similar to the measured one for 0° incidence angle.