A wearable textile antenna with dual-band and dual-sense characteristics is presented in this work. It operates at the 2.45 GHz band for WBAN and WLAN applications, and at the 1.575 GHz band for Global Positioning System (GPS) applications. An antenna backing based on an artificial magnetic conductor (AMC) plane operating at 2.45 GHz band is introduced to reduce the backward radiation and to improve antenna gain. It consists of a 3 × 3 array of square patch unit cells, where each unit cell is integrated with four square slits and a square ring. A square-shaped patch is then located on top of the substrate as its radiator. To enable dual-band operation, two corners of this radiator are truncated, with each of the four corners incorporated with a rectangular slit to enable its circular polarization characteristic in the GPS band. Simulation and experimental results are in good agreement and indicate proper antenna operation with linear polarization in the 2.45 GHz band and circular polarization in the 1.575 GHz band, with realized gain of 1.94 dBi and 1.98 dBic, respectively. INDEX TERMS Dual-band dual-sense antenna, wearable antenna, AMC plane.

Smart and interactive textiles have been attracted great attention in recent years. This research explored three different techniques and processes in developing textile-based conductive coils that are able to embed in a garment layer. Coils made through embroidery and screen printing have good dimensional stability, although the resistance of screen printed coil is too high due to the low conductivity of the print ink. Laser cut coil provided the best electrical conductivity; however, the disadvantage of this method is that it is very difficult to keep the completed coil to the predetermined shape and dimension. The tested results show that an electromagnetic field has been generated between the textile-based conductive coil and an external coil that is directly powered by electricity. The magnetic field and electric field worked simultaneously to complete the wireless charging process.

Advances in material science and semiconductor technology have enabled a variety of inventions to be implemented in electronic systems and devices used in the medical, telecommunications, and consumer electronics sectors. In this paper, a wireless charging system is described as a wearable body heater that uses a chair as a transmitter (Tx). This system incorporates the widely accepted Qi wireless charging standard. Alignment conditions of a linear three-element coil arrangement and a 3 × 3 coil matrix array are investigated using voltage induced in a coil as a performance indicator. The efficiency obtained is demonstrated to be up to 80% for a voltage of over 6.5 Volts and a power transfer of over 5 Watts. Our results and proposed approach can be useful for many applications. This is because the wireless charging system described herein can help design seating areas for the elderly and disabled, commercial systems, consumer electronics, medical devices, electronic textiles (e-textiles), and other electronic systems and devices.

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