Study of the Unit Structure in Frequency Selective Fabric Fabricated by U-Shaped Velvet

Abstract

In this study, the three-dimension (3D) frequency selective fabrics (FSFs) fabricated by U-shaped velvet, using copper wires or silver filaments as the conductive unit material, were prepared. Specimens with different unit structure parameters were experimented and analyzed. Compared to FSFs with dipole unit structure, the velvet fabrics with the same unit length have two resonance peaks in the test frequency range. With an increase of inclination angle of velvet, the resonance frequency is changed slightly, accompanied by a trend of decreasing first and then stabilizing. And the resonance frequency of the FSF would shift slowly to higher frequency under the condition of increasing the linear density of conductive ply yarns. If the total length of U-shaped unit on the bottom is greater, the resonance frequency will go to the lower one. If the total length of U-shaped unit is same, specimens with the different number of unit will have the similar resonance frequencies. This work shows that the unit structure of U-shaped velvet FSFs can be designed with more parameters comparing with planar FSF.

An electromagnetic shield design using frequency selective surfaces on a textile substrate

“…Researchers at the University of Sheffield developed knitted textile FSS [26]. A threedimensional u-shaped FSS unit cell is investigated in [27] whereas, layer to layer angle interlock 3D woven bandstop FSS is realized in [28].…”