Radio-wave shielding behavior of steel structures

Abstract

The shielding of radio wave by steel-containing structures is desirable for electronics protection but undesirable for telecommunication signal reception. This work investigates the shielding behavior of steel structures consisting of members in various configurations, with the practical aim of determining how the configuration can be exploited to control the shielding. Differently oriented continuous steel reinforcement (stranded/unstranded wires in the unidirectional, crossply and planar coil configurations) are evaluated for electromagnetic interference (EMI) shielding at 600–2000 MHz, using unpolarized radiation. The absorption loss SE A dominates the reflection loss SE R. The crossply configuration gives the highest SE A, SE A/thickness and SE A/SE T (SE T = total loss); the planar coil configuration gives the lowest values. The SE A, SE A/thickness and SE A/SE T are moderately higher for the crossply configuration than the unidirectional configuration, because steel’s electrical isotropy allows the 0° electric field to interact with the 90° wire. The SE A/SE T is comparable for the stranded and unstranded wires.