A Dual-Mode Helical Antenna Design for On-and Off-Body Communication in Body Sensor Networks

Abstract

Body Sensor Networks (BSNs) are mainly concerned with the human body. There are many restrictions concerning the sensor antenna design placed on/in the body due to harmful effects that may take place due to high power levels. Therefore, a dual-mode helical antenna resonating at the 2.4 GHz ISM band for medical application is proposed in this paper. The design includes two helices (normal and axial modes) acting as a single antenna with single feed. This combination gives the capability of serving both on-and off-body communication modes to enhance body coverage and reduce power consumption. The antenna is of a wide band from 2.2 GHz and extending beyond the 10 GHz of maximum gain of 9.67 dBi at the 2.45 GHz. The simulation results are obtained using the Ansoft HFSS software. Finally, another design of the dual-mode helix is presented using a dual-feed to give the flexibility of switching between communication modes (on-and off-body) as required.