Semi-cylindrical radar absorbing structures using fiber-reinforced composites and conducting polymers in the X-band

This paper presents a low observable structure with curved surfaces made by fiber-reinforced composites, conducting polymers and shows the possibility of developing stealth platforms for military applications. We propose radar absorbing structures (RAS) based on a circuit analog absorber in order to reduce the radar cross-section (RCS) of an object with curved surfaces. First, semi-cylindrical RAS with a periodic square patterned layer using a conducting polymer was designed and simulated by a commercial 3-D electromagnetic field analysis program. The designed semi-cylindrical structure with low RCS was then fabricated using fiber-reinforced composites and conducting polymer materials. Finally, the radar cross-section was measured in order to evaluate the radar absorbing performance of the fabricated RAS at a compact range facility. The measured radar absorption of the fabricated RAS showed that the target's RCS declined in a range of 65% to 94% within the X-band relative to a non-radar absorbing specimen.