Conformal Load-Bearing Spiral Antenna on Conductive Textile Threads

We present a novel load-bearing spiral antenna on conductive textile threads (E-threads) for conformal applications. The textile spiral exhibits a nearly 10:1 bandwidth (0.3-3 GHz) with circularly polarized gain of 6.5 dBi across the 1-3 GHz bandwidth. Such performance is unique for textiles and flexible surfaces. An important aspect of this letter is the demonstration of repeatable performance for this textile spiral antenna. Also, mechanical tests for the spiral showed no appreciable changes in performance, even after 300 flexing cycles. The spiral is a cavity-backed configuration with its ground plane also embroidered using very thin (diameter = 0.12 mm) Elektrisola E-threads. These threads can achieve geometrical precision down to 0.1 mm. To enhance robustness, high-strength Kevlar fabric was employed as the substrate. Overall, the proposed spiral is very attractive for several wideband, conformal, and load-bearing applications, such as airborne and wearables.