摘要:The laboratory measurements of the selected particle materials showed that S 244 carbon fibres,Chezacarb electro-conductive carbon black and CR 299 ground natural graphite had been effective when attenuating microwaves in a frequency range f ≈ (8-12) GHz,f ≈ (2-18) GHz,respectively. The transmittance was decreasing with the increasing thickness of the sample cell (i.e. with the increasing content of the particle material in the measuring path). The mixtures of polyamide fibres or viscose fibres with natural carbon graphite proved to be a suitable carrier of such particle material. The frequency transmittance reached the lowest values with the sample of the mixture containing 30 % of graphite.