Shielding effectiveness measurements and uncertainty estimation for textiles by a VNA-based free space transmission method

¹ Quantum Phenomenon and Applications, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-12, India
² Silicon Thin Film Solar Cells, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-12, India
³ Electrical Standards, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi-12, India

^⋆ Correspondence: patelsm@mail.nplindia.org

Received: 23 April 2013
Accepted: 12 July 2013

Abstract

A free-space transmission method has been used for reliable shielding effectiveness measurement of the easily available textile materials. Textiles with three different yarn densities were studied for their shielding effectiveness with the help of a vector network analyzer and laboratory calibrated two X-band horn antennas. The expressions of uncertainty estimation have been derived in accordance with the present free-space measurement setup for the calculated SE values. The measurements have shown that an electromagnetic energy can be maximum shielded up to 16.24 dB with measurement uncertainty less than 0.21 dB in 8.2 to 12.4 GHz range by a 160.85 μm textile. Thus, a thin textile with a high density can have higher shielding and this property mainly depends on its intrinsic structure, frequency range and thickness. This study promises the potential applications of such materials as a very cost effective shielding material at microwave frequencies with some modifications.