In this paper, the resonant coil is used in the design of wireless power transfer (WPT) to investigate the efficiency of the system. Conventional 2 coil WPT having problem in power transfer as the distance increase the PTE decreases. Therefore, this paper analyzed the effect of adding the resonant coil to the conventional 2 coil WPT. The power transfer efficiency (PTE) is analyzed by varying the diameter of coil, thickness of coil, and adding the resonant coil at both transmitter and receiver. The coil are design and simulate by using CST software and the PTE result are calculated based on the s-parameter value. Thus, from the result and analysis, the best design of WPT is by adding the resonator with efficiency of PTE above 50% with distance of 50 cm separation between transmitter to receiver with resonant frequency consistently around 13.55MHz.
