Multiband Metamaterial-Inspired Antenna with a Hexagonal Split-Ring Resonator for Multiband Wearable Application

In this study, a compact quad-band antenna inspired by metamaterials is proposed for WLAN, biomedical ISM (2.4 GHz and 5.8 GHz), and aeronautical and radio navigation applications. Specifically, a multiband metamaterial-inspired antenna with a hexagonal split-ring resonator is designed for multiband wearable applications. The proposed antenna is composed of a hexagonal split-ring resonator (SRR) and a complementary SRR, which generate four operating bands and two notch bands—one at 2.59 GHz to eliminate mobile terrestrial services and the other at 4.55 GHz to eliminate fixed mobile services. Furthermore, the wearable application is verified using a four-layer phantom model at different positions from the antenna, with the proposed antenna achieving a specific absorption rate lower than 0.4998 W/kg. Overall, the antenna is considered suitable for wearable applications owing to its broadcasting capabilities in the 2.4 GHz and 5.8 GHz biomedical bands, WLAN, and for radio-location applications, with notch bands at 2.59 GHz and 4.56 GHz helping reject the mobile communication spectrum.