The magnetic resonant coupling phenomenon has been explained
in detail using the mode coupling method [10], [11].
However, this theory is often complicated and inconvenient
when it comes to designing the circuits around the resonators.
To overcome this problem, a design and analysis method using
an equivalent circuit based on resonator and circuit design theories
was proposed in papers [15]–[18]. These papers show that
the experimental results match the electromagnetic analysis and
circuit simulations. Using the equivalent circuit, the frequency
characteristics of the resonators can be estimated up to an
accuracy of 5% error. [17] In this paper, the characteristics of
the resonators are analyzed based on the equivalent circuits and
experiments. Fig. 1 shows the resonator prototype we created
to conduct WPT via MRC