Study On The Microwave Absorbing Properties Of The Absorbing Composites With Circuit Analogue

Electromagnetic wave absorption materials can absorb electromagnetic wave and turn the electromagnetic energy into the heat one or it can make the electromagnetic wave vanished by interfering each other. The circuit analogue is made of a two-dimensional periodic array of conducting patches or aperture elements, which can improve the wave absorbing property.The single-layer carbon nanotubes/glass fiber reinforced epoxy resin composites were fabricated and the thickness of absorbing composites is0.65mm. When the content of absorbent is3%, the reflectivity below-5dB over4.80GHz bandwidth is obtained in the2～18GHz, and the maximum value of absorption is7.77dB in the16.20GHz.The multi-layer carbon nanotubes/glass fiber reinforced epoxy resin composites were fabricated. When the thickness of three-layer absorbing composites is1.95mm, the reflectivity below-5dB over9.60GHz bandwidth is obtained in the2～18GHz, and the reflectivity below-10dB over4.40GHz bandwidth is obtained, too. The maximum value of absorption is14.40dB in the11.40GHz. The multi-layer carbon nanotubes/glass fiber reinforced epoxy resin composites with circuit analogue were fabricated. When the thickness of five-layer absorbing composites is3.32mm, the reflectivity below-5dB over12.20GHz bandwidth is obtained in the2-18GHz, and the reflectivity below-10dB over6.40GHz bandwidth is obtained, too. The maximum value of absorption is24.21dB in the15.20GHz.The4080and the wool absorbing non-woven with pitch-based carbon fiber was fabricated separately. When the thickness of two-layer absorbing non-woven is7.40mm, the reflectivity below-5dB over15.60GHz bandwidth is obtained in the2-18GHz, and the reflectivity below-lOdB over14.40GHz bandwidth is obtained, too. The maximum value of absorption is21.63dB in the10.40GHz.The absorbing non-woven with circuit analogue was fabricated and the thickness of absorbing non-woven is7.40mm. The reflectivity below-10dB over13.80GHz bandwidth is obtained in the2-18GHz, and the reflectivity below-15dB over7.00GHz bandwidth is obtained, too. The maximum value of absorption is20.78dB in the6.60GHz.The absorbing coating with circuit analogue was fabricated. When the thickness of absorbing coating was1.20mm, the reflectivity below-5dB over4.80GHz is obtained in the2-18GHz, and the reflectivity below-10dB over2.80GHz is obtained, too. The maximum value of absorption is28.71dB in the12.60GHz.