The radar absorbing properties of Si-C-N ceramic powders derived from precursors have been investigated in X band (82-124GHz). When methylchlorosilanes and diphenyldichlorosilane(Ph2SiCl2) were coammonolyzed, polysilazane precursors containing phenyl were obtained which could be transformed into Si-C-N ceramic powders through subsequent pyrolysis at high temperatures and grinding. Experimental results demonstrated that Si-C-N ceramics could absorb radar in X band and that the molar ratios of Ph2SiCl2 ...