Effects of Metamaterial Slabs Applied to Wireless Power Transfer at 13.56 MHz

Table 2

Coupling coefficients, -factor, and WPT efficiencies for the free space case and for the cases of using lossless and lossy slabs.

	Slab; ()			()	(Ω)	Efficiency; (%)
EM	Free space; (1)	0.0036	473	1.7	0.1	32
	Ideal; (−1)	0.6986	473	330.4	17	98
	Ideal lossy; ()	0.1001	10.76	1.077	7	18.9
	RR slab; ( at 13.56 MHz)	0.0965	10.96	1.057	6.8	18.5
Meas.	RR slab; ( at 13.56 MHz)	0.1016	11.84	1.203	6.85	22

( = 5.5, = 0.1, = 24, = 12, = 36, and = = 6 (unit: cm)).