Systematic Analysis to Select Suitable Resonator Topology for Wireless Power Transfer Application

Electrically small inductances usually in the form of ring, circular and circular spiral coil are deployed as resonators in wireless power transfer application. Moreover, the overall Power Transfer Efficiency (PTE) of Resonant Inductively Coupled Wireless Power Transfer (RIC-WPT) system is exclusively dependent on the link efficiency which solely a function of coupling coefficient (
$k$
) and quality factor (
$Q$
) of the resonators used. This paper presents a systematic analysis of two most frequently used resonator topologies (circular coil and circular spiral coil) to outline their characteristics behavior. Different coil design dependent parameters such as mutual coupling, quality factor and transmission coefficient are evaluated and their performance corresponding to the ratio of coil radius to transmission distance are outlined so as to identify the best suitable resonator topology for WPT application. From the theoretical analysis, it is seen that the number of turns used to design the resonator differently affect the parameters like coupling coefficient and quality factor. The theoretical analyses supported by simulated results pave the way to accurately recognize and design the correct resonator for practical WPT applications.