유전손실을 갖는 유리 섬유 직물에 주파수 선택적인 탄소 섬유 직물이 삽입된 광대역 섬유 강화 전파 흡수체

초록

A broadband radar absorbing structure (RAS) covering both X and Ku bands (8.2~18.0 GHz) was designed by integrating an inductive frequency-selective carbon fiber fabric composite (FSFC) and multiwalled carbon nanotube (MWCNT)-loaded glass fabrics which can modulate EMI characteristics of the FSFC. All the layers of the structure consisted of the fiber-reinforced fabrics, and thus general composite fabrication processes can be easily applied. An existing scaling law based on the percolation theory was modified to replicate permittivity of the MWCNT-loaded fabrics. Coefficients and exponents of the power law were expressed by frequency and MWCNT concentration. The modified model provides a good description of the dielectric property of MWCNT fabric composites, and thus paves the way for parametric evaluation of reflection loss of the FSFC-embedded double-layered RAS regarding the permittivity of the lossy dielectrics, as well as thickness of each layer and the total thickness of the RAS.