The electrical conductivities of steel and other candidate materials for shrouds in a beam-waveguide antenna system

This article presents the results of electrical conductivity measurements made at 8.420 GHz on samples of the structural steel material used to fabricate shrouds on a Deep Space Network (DSN) 34-m-diameter beam-waveguide (BWG) antenna. Test results show that the structural steel samples at this microwave frequency had effective conductivities that were about 50 times worse than published dc values and also 230 times worse than the measured conductivities of aluminum test samples. Conductivity data are also presented for other candidate materials that could be used to fabricate BWG shrouds. Of interest are the improvements or degradations that were observed after some of the metal test samples were surface treated, plated, or painted.