A multi-band planar antenna for biomedical applications

We present the design of a compact tri-band adhesive planar antenna which operates as a gateway for biomedical applications. Operating in the Industrial, Scientific and Medical (ISM) band (2.4-2.5 GHz), the Institute of Electrical and Electronics Engineers (IEEE) 802.15.6 Wireless Body Area Network Ultra-Wide Band (WBAN UWB) (3.1-10.6 GHz) and the IEEE 802.11 Wireless Local Area Network or WLAN (WLAN) band (5.15-5.725 GHz), the antenna is useful in the context of body-signal monitoring. The ISM band is used for in-body communication with the implanted medical devices, whereas the WBAN and WLAN bands are for off-body communication with the base station and central medical server, respectively. We have designed our antenna to operate at 2.34/3.20/4.98 GHz. The simulation results show that the antenna has 10 dB bandwidths of 420 MHz (2.07-2.49 GHz), 90 MHz (3.16-3.25 GHz), and 460 MHz (4.76-5.22 GHz) to cover the ISM, WBAN, and WLAN bands, respectively. The proposed antenna is printed on a flexible Rogers RT/duroid 5880 epoxy substrate and it occupies a compact volume of 24 x 24 x 0.787 mm. The designed antenna is simulated using HFSS and the fabricated antenna is experimentally validated by adhering it to a human skin. The simulated and measured performance of the antenna confirms its omnidirectional radiation patterns and high return losses at the three resonant bands.