Design of a Wearable Antenna Using Metamaterials

Abstract

This study focused on developing and testing a flexible dual-band (2.4 GHz, 5.2 GHz) wearable dipole antenna, examining its return loss, gain pattern, and specific absorption rate (SAR) under different bending scenarios (E-plane, H-plane) across various human body regions such as the arms and legs. The antenna utilized felt, a clothing material, as a dielectric, and Zelt as a conducting patch to ensure flexibility and conformity. By maintaining resonant frequencies as required, the design prevented detuning during wearable use. Furthermore, compared to traditional designs, the antenna exhibited an increased gain of up to 4.45 decibels (dBi). Incorporating metamaterials into the design led to a significant reduction in SAR, addressing a common issue with omnidirectional wearable dipoles. The use of an electromagnetic bandgap (EBG) ground plane resulted in an 83.3% and 92.8% reduction in SAR for 2.4 GHz and 5.2 GHz respectively, meeting acceptable levels defined as less than 2.0 W/Kg over 10 g of tissue. Consequently, the dual-band dipole based on metamaterials proved to be compact, low-profile, flexible, and outperformed conventional counterparts in wearable technology applications.