Computation of radar absorbing silicon carbide foams and their silica matrix composites

SiC-foams and their composites were studied as novel stealthy materials by numerical simulations. The reflection coefficients of various SiC-foams are found to be strongly dependent on the SiC volume fractions, electric conductivities and frequency. A foaming SiC allows to reach high level of electromagnetic wave absorbing ability when the SiC volume fraction and the conductivity at proper values comparing to SiC-particles and SiC-bulk, Which due to an increase of electromagnetic energy dissipation in foaming structures and an improvement of the conjugation condition with free space. It is of most importance that SiC-foams exhibit artificial magnetic properties that can absorb the magnetic energy of electromagnetic waves. The electromagnetic absorbability of the silica composites are significantly decreased compared to that of the SiC-foams alone for the larger impedance mismatch with free space.