Wearable triband E-shaped dipole antenna with low SAR for IoT applications

Abstract

This paper presents a novel design of a flexible and wearable E-shaped, multiband dipole antenna. The antenna has a low profile and is printed on a common 2 mm thick denim fabric (εr = 1.7). By installing a passively coupled rectangular patch with L-shaped cuts, the lower frequency band is supported and the bandwidth at higher frequencies is also enhanced. The antenna’s performance was observed under different deformations in free space as well as when it was placed on different parts of the human body. No significant changes in the characteristics of the frequency bands of interest were observed for the flexible antenna compared with the initial nondeformable antenna. Simulations for 10 g average specific absorption rate (SAR) at different input powers up to 250 mW were carried out considering that the antenna adheres well to the human body and there is no spacing or shielding. The obtained results show that the amount of energy absorbed by the body tissue increases by increasing the incident power.