Body-Worn 30:1 Bandwidth Tightly Coupled Dipole Array on Conductive Textiles

Abstract

We present a novel tightly coupled dipole array (TCDA) based on conductive textiles (E-threads) that achieves 30:1 bandwidth across the 60–2000 MHz frequency range (VSWR < 4). The proposed antenna occupies 1.4 m in length and 0.05 m in width and consists of three overlapping dipoles that are fed in phase to ensure uniform current flow. Two fabricated prototypes are presented in this letter. The first is a rigid metallic version using a 1.524 mm thick Rogers RO4003 board via conventional printed circuit board fabrication. The other is a fully flexible textile-based prototype “printed” on organza fabric via automated embroidery of conductive threads (E-threads). In both cases, measurements are in very good agreement with simulations. Specifically, the TCDA is well matched from 500 to 2000 MHz with VSWR < 2.5 and has a realized gain ranging from −16 to 6 dBi across the entire bandwidth from 60 to 2000 MHz. The proposed design is intended for on-body operation (e.g., placed along the arms). To assess the performance of this antenna for body mounting, we applied a 2 cmthick ground beef beneath the textile TCDA to represent the body tissue. Overall, the proposed TCDA brings forward new opportunities for several ultrawideband applications.