Optimization of the microwave absorptivity of SiCf/Resin composites in the GHz range

The effects of structural factors on the electromagnetic wave absorption properties of SiC fibre reinforced resin composites (SiCf/Resin) were investigated. Transmission line theory was used to calculate the reflection loss and to tap the potential of SiC fibres as broadband wave absorbents. The structure of the SiCf/Resin composite was optimized based on a double-layered laminate containing high-resistance SiC fibres (H-SiCf, rho = 6.5 x 105 0 cm) in the upper layer and low-resistance SiC fibres (L-SiCf, rho = 109.7 0 cm) in the bottom layer. The calculation suggests that to achieve a high absorptivity better than -10 dB, the permittivity of the L-SiCf/Resin bottom layer must be enhanced to quite a high value with a specific frequency dispersion degree. The desired permittivity was realized by controllable addition of carbon black into L-SiCf/Resin. Under the optimized thickness combination, the reflection loss of the double-layered composite could be lower than -13.3 dB in the whole X and Ku bands.

Automated summary

The study investigated the effects of structural factors on the electromagnetic wave absorption properties of SiC fibre reinforced resin composites. By utilizing transmission line theory, the structure of the composite was optimized to achieve high absorptivity in the X and Ku bands. Through controlled addition of carbon black, the desired permittivity of the composite was realized, resulting in reflection loss lower than -13.3 dB.