• Composites Research
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• v.23 no.2
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• pp.17-23
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• 2010

The stealth technology can increase the survivability of aircrafts or warships and enhance the capability of mission completion in hostile territory. The purpose of this paper is to present the low observable structure with curved surfaces made by fiber-reinforced composites and to show the possibility of developing omnidirectional stealth platforms for military applications. In this study, we developed a radar absorbing structures(RAS) based on a circuit analog absorber to reduce the radar cross section(RCS) of an object with curved surfaces. Firstly, the RAS with a periodic square patterned conducting polymer layer was designed and simulated using a commercial 3-D electromagnetic field analysis program. Secondly, the designed semi-cylindrical structure with low RCS was fabricated using fiber-reinforced composites and conducting polymer. To make the periodic pattern layer, acts as resistive sheet, the intrinsic conducting polymer paste containing PEDOT with a polyurethane binder was used. Finally, the radar cross section was measured to evaluate the radar absorbing performances of the fabricated RAS by the compact range facility in POSTECH.

• Composites Research
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• v.36 no.5
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• pp.335-341
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• 2023

We proposed a high-temperature circuit-analog radar absorbing structures (CA-RAS), and evaluated radar absorption performance and tensile properties in 350℃ and a hot-wet environment. The CA-RAS was implemented with a glass/cyanate ester composites and a square resistive pattern layer, and reflection loss was measured by 350℃ and after exposure of hot-wet condition using free space measurement. And the tensile strength at 350℃ and after exposure of hot-wet condition was measured according to the ASTM D638. The proposed CA-RAS showed a 4 GHz of -dB bandwidth and -20 dB of a peak value at 350℃. In addition, there was no deterioration in absorption performance after exposure to a hot-wet condition. The tensile strength value of more than 95% compared to the strength of the glass/cyanate ester composite was confirmed at 350℃ and after exposure of hot-wet condition. Through this, the applicability of CA-RAS proposed in this study was confirmed as a load bearing structure for stealth weapon exposed to high temperature and hot-wet environment.