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

Abstract

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.

Car Bumper Effects in ADAS Sensors at Automotive Radar Frequencies

“…If we calculate the relative uncertainty, i.e., normalized by the mean value (Figure 10), we can observe that, in general, it is more difficult to measure the attenuation with precision as the frequency grows. These values of uncertainty agree with those reported in [44] for shielding effectiveness measurements in textiles. The free-space transmission method was also used by these researchers, but the equipment used was a vector network analyzer (VNA).…”

“…The free-space transmission method was also used by these researchers, but the equipment used was a vector network analyzer (VNA). In [45,46], un- These values of uncertainty agree with those reported in [44] for shielding effectiveness measurements in textiles. The free-space transmission method was also used by these researchers, but the equipment used was a vector network analyzer (VNA).…”

Nanometer-Thick Sol–Gel Silica–Titania Film Infused with Superparamagnetic Fe3O4 Nanoparticles for Electromagnetic Interference Shielding

“…The EMI shielding effectiveness was calculated from the S-parameters, where S 11 is equivalent to the input complex reflection coefficient and S 21 is the forward complex transmission coefficient (Figure S6). 50,51 ■ ASSOCIATED CONTENT * sı Supporting Information…”

“…The Fe 3 O 4 –STO thin films are expected to show some interaction with the electromagnetic wave (EMW) since it was reported that Fe 3 O 4 material may increase the EMW absorption property of composite materials in the range of 1–20 GHz. − The reflectance ( R ), absorbance ( A ), and transmittance ( T ) of a shielding material can be obtained by measuring the scattering parameters ( S -parameters) for each frequency band . The EMI shielding effectiveness of the Fe 3 O 4 –STO film, which contributed to the absorption and reflection of the embedded CA-Fe 3 O 4 NPs, may be described by the following relation. − where S 21 0 is the transmission parameter of pure STO film and S 21 ′ is the transmission parameter of the Fe 3 O 4 –STO nanocomposite thin film.…”

Electromagnetic shielding performance of copper and silver-plated hybrid yarn based multilayer fabrics in C & X band frequency range

“…However, some researchers recommended “Free-space method” to characterize complex electromagnetic properties of polymeric and textile materials. Patel et al 2013 [18] found it as reliable measurement method for textile materials. Dvurechenskaya & Zielinski 2011 [19] in their study opted free-space transmission technique for investigation of woven and non-woven (anisotropic materials).…”