Preparation of knitted fabric-based frequency selective surface and its frequency response characteristic

To study the frequency response characteristics of knitted fabric-based frequency selective surface (FSS), high-pass knitted fabric-based FSS were designed and prepared. The electromagnetic transmission characteristics were tested in a microwave anechoic chamber. The results show that weft-knitted fabric based FSS has high-pass and low-resistance electromagnetic properties. When the placement direction of the knitted fabrics and the polarization mode of electromagnetic wave are different, the frequency response characteristics are distinct. When the ratio of conductive yarns increases, the electromagnetic wave shield ability and breathability of knitted fabric based FSS are enhanced. The shielding ability of the fabric increases with the density, but the permeability of the fabric decreases. As the incident angle of electromagnetic wave increases, the electromagnetic wave component entering the fabric decreases, and the electromagnetic wave passing through the fabric decreases. Therefore, under the premise of wear comfort, the frequency response characteristics of knitted fabrics can be controlled and selective transmission of electromagnetic wave can be achieved by designing the structure and weaving parameters of knitted fabrics and adjusting the polarization mode and incidence angle of electromagnetic wave.