A Novel Clothing-Based Nest-Inspired Resonator for Wireless Power Transfer and Harvesting

In this paper, a new topology for textile-based wireless power transfer and harvesting system is presented. it consists of a nest-inspired resonator that concentrates the electric and magnetic fields in the center and within the periphery of the nest, respectively for robust electromagnetic field presence to tackle the misalignment problem. The resonator was designed and simulated to operate at 433 MHz. This design enabled high power transfer efficiency (PTE) when the resonator was under the influence of lateral misalignment along the direction of the RF current. The results suggest a PTE of up to 82.5% within 10 cm of displacement. This is 10% improvement over the PTE of a single loop operating at the same frequency. The diagonal misalignment showed a PTE of up to 77.5% within 10 cm of misalignment. This is up to 20% of improvement over that of the single loop. A textile-based power harvesting circuit operating at 433 MHz with an RF-to-DC conversion efficiency of 82% at 500 mW is proposed to be integrated with the resonator. A combination of the resonator and power harvesting circuit will be implemented on an ad-hoc on-body charging solution.