Wearable wireless sensors are a part of human life in the future for applications such as healthcare, sports, navigating, security etc. The number of wearable wireless sensors for fitness and healthcare applications will reach 90 million shipments by 2017 base on ABI research report [1]. The IEEE Standard 802.15.6 for local and metropolitan area networks, part 15.6, “Wireless Body Area Networks” was published on February 2012 to specify the short range wireless communication in the vicinity or inside of the human body [2]. This shows the importance of research needed to maximize the quality of wireless communications around the body. The human body is a lossy medium that absorbs the radio frequency (RF) energy and this affects the propagation of electromagnetic waves used in wireless communication. The specific absorption rate (SAR) is defined by the Federal Communications Commission (FCC) to identify criteria for measuring the rate of absorption and amount of interaction between the body and a source of RF energy [3].