The Study and Application of Nanocarbon Materials in Radar Absorbing Structures

• Main Authors: Chun-chung Teng, 鄧淳中
• Other Authors: Ruey-bin Yang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/59896274283653125270

碩士 === 逢甲大學 === 航太與系統工程所 === 98 === The radar absorbing structures (RAS) are multifunctional composites with dual functions of high strength performance and radar cross section (RCS) reduction. To improve the bandwidth of RCS, a circuit analog RAS is fabricated by replacing the resistive sheet of a Salisbury screen by a frequency selective surface (FSS). This dissertation is aimed to the design, analysis and manufacturing of circuit analog absorbers with broadband, light-weighted and excellent strength properties. Conductive nano-fillers such as carbon black and multi-walled carbon nanotube (MWNT) mixed with epoxy resin are added to honeycombs in an attempt to efficiently increase the absorbing capacity of RAS. The microwave absorbing composites samples are fabricated by mixing with epoxy resin and absorbent fillers in different weight ratios. The complex permittivity and permeability of composites are measured and the maximum absorption is -25.97 dB (at 9.76 GHz) for carbon black absorbers and -36.46 dB (at 8.24 GHz) for MWNT absorbers with 3 mm thickness. The FSSs are fabricated by a screen printing method with the conductive carbon ink instead of the costly sputtering method. The RAS with two FSSs are specially designed with 5 wt% carbon black or 10 wt % carbon nanotube embedded in the honeycombs so as to exhibit the 10 dB absorptivity in the frequency range of for 4-18 GHz.