Design and Characterization of Purely Textile Patch Antennas

TLDR

Textile materials and planar antenna shape enable smooth integration into clothing while preserving typical textile properties. The study presents four purely textile patch antennas for Bluetooth wearable computing around 2.4 GHz. The authors fabricated four textile patch antennas differing in materials and polarization, all fed by a microstrip line, using a manufacturing process that preserves electrical behavior and achieves sheet resistance below 1 Ω/square, and they characterized performance in planar and bent configurations resembling worn garments. The manufacturing process meets Bluetooth accuracy requirements, and the antennas tolerate garment bends down to 37.5 mm without violating specifications.

Abstract

In this paper, we present four purely textile patch antennas for Bluetooth applications in wearable computing using the frequency range around 2.4 GHz. The textile materials and the planar antenna shape provide a smooth integration into clothing while preserving the typical properties of textiles. The four antennas differ in the deployed materials and in the antenna polarization, but all of them feature a microstrip line as antenna feed. We have developed a manufacturing process that guarantees unaffected electrical behavior of the individual materials when composed to an antenna. Thus, the conductive textiles possess a sheet resistance of less than 1Omega/squarein order to keep losses at a minimum. The process also satisfies our requirements in terms of accuracy meeting the Bluetooth specifications. Our investigations not only characterize the performance of the antennas in planar shape, but also under defined bending conditions that resemble those of a worn garment. We show that the antennas can withstand clothing bends down to a radius of 37.5 mm without violating specifications