Characteristic Analysis of Double Spiral Resonator for Wireless Power Transmission

In this paper, we focused on comprehensive analysis and experiment of a unique resonator pattern, named “double spiral resonator” in wireless power transmission (WPT) via resonance coupling, which is suitable for printing on ultra-thin and low-cost substrates such as paper or film with ink-jet printing technology. By conducting contrast experiments with other two patterns of resonators, the comparing result shows that double spiral resonator ensured higher peak transmission efficiency in longer distance. Five structural parameters of double spiral resonator have been investigated for the effect on the peak transmission efficiency concerned. Also, equivalent circuit (EC) analysis of peak transmission efficiency has also been derived to find the theoretical explanation of the phenomenal parameters' effect on transmission efficiency. We also contributed by exploiting electromagnetic (EM) field calculation method to obtain the coupling coefficient of two double spiral resonators at different distances via the parasitic parameters of the resonators. Lastly, we also conducted a discussion on how parameters can affect the quality factor Q of double spiral resonator.