Influence of hole on shielding effectiveness of electromagnetic shielding fabric under incident polarization wave

Abstract

Purpose – The purpose of this paper is to explore the influence of hole on shielding effectiveness (SE) of electromagnetic shielding (EMS) fabric under incident polarization wave, and to propose a “Key Size” theory to explain the influence mechanism. Design/methodology/approach – “Key Size” parameters describing hole shape are established, and a number of representative samples with rectangular and oval holes are made. SE of the samples are tested by waveguide testing system. Influence of the hole on the SE of the samples is analyzed according to vertical or horizontal maximum size and polarization wave direction. Finally, the “Key Size theory” and “Secondary Size theory” are proposed to explain the influencing mechanism. Findings – The hole influences on the SE are related to the vertical and the horizontal maximum size of the holes and the direction of the polarization wave. As the direction of the polarization wave is vertical (or horizontal), greater maximum size results in lower SE. As the maximum size is constant, greater maximum size causes lower SE. As the maximum size reaches to a certain value, a dividing point of the SE occurs. As the direction of the polarization wave is consistent with the direction of the maximum size, same hole area results in same SE. Originality/value – The explored influences and mechanism provide an important guiding reference for the hole design of the EMS fabric, and can be applied to the holes design of the EMS garment, composite materials, and tents.