Effect of sewing types on flexible embroidery antennas in UHF band

In this paper, two flexible fabric antennas in UHF band are chosen to study the effect of three sewing types on performances of embroidery antennas. A meandered sleeve monopole antenna is embroidered into a jean cotton substrate with Fill stitch and Spiral stitch respectively. From measured return loss and received power, the antenna with Spiral stitch shows better performances. In the same way, a disc antenna is embroidered into a jean cotton substrate with horizontal Fill stitch, vertical Fill stitch and concentric circle stitch respective. The measured results confirm that the concentric circle stitch is more suitable for disc antenna design. Thus it can be concluded that different textile antenna designs should choose different sewing types to obtain good antenna performances.