A low SAR and ultra-small highly flexible wearable off-body biomedical antenna in wireless applications

Presented in this study is a compact, dual-band, and highly flexible inverted slotted triangular-shaped monopole antenna. It is backed with a dual-band artificial magnetic conductor for off-body wireless and low specific absorption rate (SAR) medical applications. The antenna is designed to radiate at 2.45 GHz of the Industrial, Scientific, and Medical-band and achieves dual-band resonance by etching two inverted L-shaped slots off the monopole antenna. By doing so, the antenna operates at 5.2 GHz of the wireless local area network frequency band. In off-body operation, the integrated design achieves gain improvements at both operating frequencies by 6 and 4.9 dBi, respectively, compared to the standalone antenna. In the case of the on-human-body operation scenario, low SAR levels of 0.39 and 0.07 W/kg were realized at both resonant frequencies, respectively. The proposed integrated design was fabricated and tested, where the tested results highly align with the simulated ones in free space and on-body cases. The antenna size is only 39 × 25 mm 2 which is claimed to be an ultra-size. Thus, the presented antenna is claimed to be very competitive in terms of the small size and the achieved antenna parameter results.