Impact of Body and Clothing on a Wearable Textile Dual Band Antenna at Digital Television and Wireless Communications Bands

A dual band textile antenna designed for Digital Television (DTV) and many wireless standards including GSM 900, WLAN 2.45/5.8 GHz, Wimax 3.5 GHz, Hyperlan 5.2 GHz and UMTS-LTE-advanced is described. The impact of the body on antenna performance is assessed for return loss, radiation patterns and antenna efficiency in a wide frequency range. Full three dimensional radiation patterns were measured with the antenna backed by a phantom in order to simulate a human body. While the return loss was found to be only marginally affected when the antenna was mounted at various positions on the human body, the measured efficiency was observed to decrease by up to 90% when the antenna was positioned flush to the phantom. The return loss response was little affected when the antenna was worn on the back and further covered with a number of garments including a thick woolen jumper and a ski jacket. Although antenna efficiency was substantially affected by the presence of the body, interposing a layer of felt fabric between the antenna and the phantom typically improved efficiency by over 50%. This unique soft antenna is a good candidate for receiving digital television and wireless communications in a smart clothing environment.