Wearable Textile Shielded Stripline for Broadband Operation

A shielded stripline structure made from textile materials is introduced as a wearable flexible transmission line for broadband operation. The stripline with a total height of 3.2 mm consists of a foam substrate and silver fabric conductors. For shielding purpose, the structure is truncated on its sides at a total width of 20 mm using embroidered via walls made from conductive thread. The impedance bandwidth and propagation characteristics are investigated through simulation and experiment, demonstrating that the textile stripline can work efficiently and reliably from dc to 8 GHz. Moreover, it is shown that the textile stripline is robust in terms of propagation characteristics, as even when bent up to 90° and 180° it can maintain consistent propagation properties in the whole operation band. A further advantage of the structure is the simple fabrication, arising from the low sensitivity of the structure to width and height tolerances, as well as to the accuracy of the feeding method. Finally, it is shown that the low-loss radio frequency foam substrate material can be replaced with low-cost clothing felt without significant detrimental impact on the efficiency.