A novel dual-mode antenna for on-body and off-body communications is proposed. In on-body mode, the antenna is similar to a pair of metal electrodes operating at 10MHz and in off-body mode, with an L-shaped slit embedded, the antenna can cover the 2.45 GHz ISM band. Measured results, including received voltage at 10 MHz, reflection coefficient and radiation patterns in the 2.45 GHz ISM band are presented to validate the proposed antenna.Introduction: Recently, the advance of electronic devices is leading to the creation of body-centric wireless communications (BCWCs), in which wireless devices are attached to the human body. With these devices, as an important application of BCWCs, remote health monitoring, will become real [1,2]. In remote health monitoring, at least two modes of communication are required: on-body communications (collecting medical data) and off-body communications (exchanging data with outside networks). For on-body communications, relatively low frequency bands (tens of MHz) are more suitable [3,5], while for off-body communications, the 2.45 GHz ISM band (2.40-2.48 GHz) is a good candidate [6]. Thus, a dual-mode antenna is a key component for remote health monitoring. To the authors' knowledge, this is the first time a study demonstrates such a kind of antenna. In on-body mode, the antenna is similar to a pair of metal electrodes operating at 10MHz and in off-body mode, with an L-shaped slit embedded, the antenna can cover the 2.45 GHz ISM band.

Body-centric wireless communications (BCWCs) have received increasing attention due to its potential application in areas such as E-health systems, home care, security, and entertainment. A compact and low-profile wearable planar inverted-F antenna (PIFA) with tuning function is presented for BCWCs in this paper. A two-thirds muscle-equivalent phantom is used to model the human's arm. By tuning the proper capacitance of the proposed antenna, the industrial, scientific and medical (ISM,2.40-2.48 GHz), wireless broadband (WiBro, 2.3-2.39 GHz) and Universal Mobile Telecommunications System (UMTS, Rx 2.1-2.17 GHz) and meanwhile lower band can also cover 950-956 MHz.