Parametric analysis of helical resonators for resonant wireless power transmission links

This paper presents a parametric study of wireless power transmission links composed of two identical helical resonators. The effect of the helix radius, the pitch and the number of turns are studied in order to find the optimal geometry that maximizes the transmission efficiency. The product of the coupling coefficient and the quality factor is used as a figure of merit to compare the different structures. A practical validation is presented and it shows that the simulations predict accurately the frequency response of the link. We demonstrate that the best performance is achieved when the radius is equivalent to approximately 75% of the transmission distance.