Wearable Ring Resonator Antenna

In this paper a metamaterial wearable antenna is proposed. The proposed design is based on a transmission line coupled to a pair of double ring resonators (DRRs) on an e-textile substrate. The metallic antenna layer is fully embroidered providing both electromagnetic and mechanical good properties. The proposed design is validated by comparison of 3D electromagnetic simulations and measurements. The obtained results correspond to S-11 < -29.5 dB with a gain of 9.64 dBi at resonance frequency and 93% efficiency covering a 160 MHz bandwidth. In addition, the effect of environmental condition such as temperature and humidity on antenna is reported. Results show the resonance frequency level shift in several climatic conditions. Moreover, the specific absorption rate (SAR) to preserve the human body safety from radiation is performed by means of numerical simulations, according to the international regulation. Experimental results confirm that the embroidered MTM antenna is a useful technique to control the propagation of signals on wearable applications.