A square ring and single split resonator based wearable antenna for Microwave energy harvesting for IoT nodes

Abstract

A wearable antenna utilising metamaterial radiating elements, which operates at two frequency bands, are presented in this paper. A closed-ring resonator and a single split-ring resonator of square shape have been used to provide dual resonance. The work develops a compact microstrip patch antenna having radiating patch dimensions of 24.8 × 24.8 mm2, that generates electromagnetic energy exhibiting dual band from 2.3 to 2.5 Giga Hertz (WiMAX, ISM) and 3.4 to 3.6 Giga Hertz (WiMAX band). This work provides relevant parametric analyses, such as free space, on-body, and antenna bending effects. Microstrip antenna is designed to be built on flexible dielectric substrate named Rogers RT-5880 Material with dielectric constant 2.2 and thickness of 0.787 mm. The design is validated by a comparison of numerical and actual antenna measurements. Between simulated and measured findings, good equivalence has been discovered. The fabricated antenna provides an impedance bandwidth of 1036 Mega Hertz in lower and 352 Mega Hertz in upper-frequency range, a gain of 2.7 dB,2.35 dB, the directivity of 3 dB, 2.9 dB, the radiation efficiency of 93.32%,88.21 % at 2.4 and 3.6 Giga Hertz respectively in free space condition. The results highlight the applicability of an energy efficient dual-band proposed antenna in wearable applications and microwave energy harvesting for IoT nodes within the ISM and WiMAX bands.