Wideband textile-based conformal antennas for WLAN band using conductive thread

Abstract

Low profile conformal antennas using conductive thread at WLAN-band, are presented. The radiating elements are printed on the textile materials. The relative dielectric constant of the textile Samples Under Test (SUT) are extracted using the resonance method. An error of 5 % is observed in the extracted dielectric constant, when performance of WLAN antenna is measured at WI-FI Band. To make the antenna conformal, solid ground plane at the bottom of antenna is replaced with shielded fabric with high level signal attenuation. Multi-bowtie planar antenna is designed with conductive thread and further analyzed its performance in the conformal environment. Later, to increase the bandwidth of conformal antennas, stacked multi-bowtie antenna, and conformal DRA antenna on the textile materials, are designed. The designed antennas provide more than 30 % matching bandwidth, and the maximum radiation efficiency of 98 % (at 2.45 GHz). The thinnest available 0.17 mm thick double sided adhesive tape, has been used on the back of the proposed conformal antennas, that makes the antennas installation easier by peeling and sticking with the body. The proposed methods provide promising steps towards designing wide band flexible conformal antennas.