Study of radio transparency and dielectric permittivity of glass- and aramid epoxy composites

Abstract

Aramide- epoxy-filled composites are widely used for manufacturing in the structures of modern aerospace vehicles. Not only do they have excellent mechanical properties, but they are also radio-transparent materials for wave transmission. In this work, an epoxy-filled composite and a fibreglass were made by vacuum infusion for a comparative study on radio transparency and dielectric permittivity. The radio transparency of the materials analyzed has been evaluated by measuring in free space in the frequency ranges of 1-6 GHz. According to the results of radio transparency, aramide- epoxy-filled composite suffers less electromagnetic wave losses than in fibreglass. When measuring the dielectric permittivity of the aramide- epoxy-filled composites, a low average value of 2.874 has been set, whereas for the fibreglass is defined at 4.