A 10∶1 bandwidth textile-based conformal spiral antenna with integrated planar balun

We present a novel wideband conformal slot spiral based on embroidered electrically conductive fibers (e-fibers). Such e-fibers are composed of high strength and flexible Zylon core covered with a 2~3 μm metallic coating. Using these e-fibers, highly conductive textile surfaces were precisely fabricated using computerized embroidery machinery. A unique aspect of the proposed conductive textiles is their inherent mechanical flexibility over traditional metals, in addition to their low electrical loss. A textile-based slot spiral was fabricated and shown to achieve a 10:1 bandwidth from 300 to 3000 MHz with near consistent circularly polarized gain of 5 dBi over the band. Such performance has never before been achieved using textile antennas, and/or flexible surfaces. As such, software radios and wideband beamforming can be achieved using antennas woven into clothing or embroidered into non-planar surfaces of any shape and detail.