Stitched transmission lines for wearable RF devices

A novel stitched transmission line for wearable devices has been manufactured and tested to measure its scattering parameters from 0.04 to 4GHz. The stitched transmission line which is 150mm long consists of an inner conductor surrounded by a tubular insulating layer. For shielding purpose, the structure is stitched onto a denim material with a conductive thread with the aid of a novel manufacturing technique using a standard hardware. The S-Parameters were investigated with three different stitch angles 85°, 65° and 31° through simulation and experiments, demonstrating that the stitched transmission line can work usefully and consistently from 0.04 to 4GHz.