Experimental Verification of the Shielding Properties of Selected Textile Materials in the X Frequency Band

Abstract

The increasing development and application of wireless devices and systems that radiate electromagnetic waves makes electromagnetic interference (EMI) shielding more and more important in everyday life. In practice, rigid EMI shields are the most commonly used ones. However, for humans or in automotive and aviation applications, flexible, drapable materials, such as textile fabrics, can be more effective and useful. Textile fabrics are usually nonconductive and not magnetic, i.e., they lack the requirements for EMI shielding. However, shielding properties of textile fabrics can be achieved by blending yarns with fine wires or coating fibers or by blending complete textile layers with conductive or magnetic materials. In this paper, shielding textile fabrics and 3D-printed materials, as references with different conductive (and partly also magnetic) properties, are examined. The measurements show a high shielding effectiveness of 80 dB given by densely woven fabrics with a thin metallic coating in the frequency range of 6.5–11 GHz, while large pores in crocheted fabrics significantly reduce the EMI shielding effectiveness, and other samples did not show shielding at all, suggesting that a combination of conductivity and the structure of the samples is responsible for the shielding potential.

Keywords

• electromagnetic interference (EMI)
• shielding effectiveness
• conductive coating
• metallized fabric
• conductive yarn
• crocheted fabric