No abstract

No abstract

In this study, we present a comprehensive dual-band ambient radio-frequency (RF) energy harvesting system, consisting of rectenna and power management circuit, to harvest energy from 2.45 and 5.8 GHz Wi-Fi. The rectenna employs a metamaterial antenna based on a split-ring resonator, which possesses omni-directional radiation pattern at both frequencies and compact size (0.18λ × 0.25λ at 2.45 GHz). The dual-band rectifier yields the highest efficiency of 42% at 2.45 GHz and 1 dBm input power, 30% at 5.8 GHz and − 7 dBm input power. The maximum RF-DC efficiency for each band is 72% at − 5 dBm and 27% at − 2 dBm, respectively. The power management circuit, consisting of a storing capacitor and a boost converter, is integrated to produce a stable, sufficient output voltage. The energy harvesting system, with its comprehensiveness, is suitable for supplying low-power wireless sensor nodes for indoor applications.

No abstract

This paper presents a novel dual-band ambient Wi-Fi energy harvesting system for an autonomous wireless sensor node (AWSN) which operates independently without other external power source. While conventional wireless sensor nodes employing batteries with limited lifespans, an AWSN is supplied by harvested energy and does not require frequent battery replacement. Due to that reason, research on the energy harvesting aspect of AWSNs has been carried out intensively in recent years. By optimizing the matching network, the proposed ambient Wi-Fi energy harvesting system achieves a relatively good efficiency in dual-band at 2.45 GHz and 5.8 GHz. The efficiency reaches a peak at 47.45 % and 42 % at 2.45 GHz and 5.8 GHz, respectively. The proposed idea is numerically and experimentally demonstrated with the Wi-Fi source in building.