Ultra wideband loop antenna on contact with human body tissues

Human body tissues have a strong effect on the antenna operation in wireless body area networks (WBANs). In this study, the authors present the deep investigations of the effect of body tissue thicknesses on the performance of an ultra wideband (UWB) loop antenna by simulations when the antenna is operated on contact with tissues. The planar UWB loop antenna is designed for the examinations, which is targeted to be used in UWB WBAN applications. The effect of tissue thicknesses on the antenna performance is analysed and characterised in the terms of reflection coefficient S₁₁, gain and total antenna efficiency, group delay, radiation patterns and specific absorption rate by simulations. A parametric layered human body tissue model with the frequency-dependent behaviour is exploited in the investigations. Further, the reflection coefficient of the presented antenna is measured in the different locations of the author´s body. The main aim of these investigations is to demonstrate how the thickness of outermost body tissues affects the antenna performance.