A Wideband Circularly Polarized Jeans-Based Antenna at 2.45 GHz

Development of textile antennas is an important segment towards the goal of creating smart clothing. In this paper, we report on a jeans-based circularly polarized textile antenna designed for the E-band (around 2.45 GHz). We present three variations of the design and the respective results. The antenna comprises a multi-layer jeans-fabric as the substrate, a conductive fabric as the patch, which is concealed with another layer of jeans, and the ground plane is formed by either a cooper foil or another conductive fabric. A multi-layer structure was chosen to provide a wider bandwidth and better efficiency, whereas the upper surface of the antenna was covered by one more layer of jeans to both make the antenna less conspicuous, when worn on the arm, and protect the patch and substrate from mechanical damages and moisture. All three variants are characterized by a good realized gain of about 3 dB, a wide beam width and a wide bandwidth of 21% or better, around 2.45 GHz, having the radiation efficiency around 36%, and front-to-back ratio of 5 dB or better, with the ground plane being just slightly larger than the patch.