EMI Shielding and Reflection From Textile Mesh Grids Compared With Analytic Models

In this paper, new textile-based shielding materials are presented. The woven textile mesh grids (2 × 2 and 4 × 4 mm
²
) are made with the use of three different types of conductive threads based on polyester yarn twisted together with steel filaments, silver-plated polyamide filaments, and silver-plated copper filaments. The conductive threads are characterized by SEM images. The transmission and reflection coefficients over the wide frequency range from 2.6 to 18 GHz are measured and analyzed using a rectangular waveguide method in a TE10 mode. The measurement results are verified and validated by two types of model analysis: theoretical analysis based on the metal-grid approach and filter model analysis based on the equivalent circuit theory. The unknown model parameters in the two cases are determined with the use of an optimization procedure that is specially designed for the scalar measurement data.