This article presents a novel approach to improve the efficiency of a radiative near‐field wireless power transfer (WPT) system by using metasurface. The WPT system is designed particularly for implantable applications, which operate at the industrial, scientific, and medical (ISM) 2.40–2.48 GHz band. To construct the WPT link, a patch antenna is used as the transmitting element whereas a small planar loop antenna is considered as the receiving element. The receiving antenna is implanted under the skin tissue model operating at 2.45 GHz. The metasurface with a high refractive index is placed above the surface of the skin layer to improve the power transfer efficiency. Regarding the motion of the human body, different misalignment tolerances between the transmitter and the implant receiver are discussed. Also, the effect in the change of the skin property and placement depth of the Rx antenna inside the skin tissue model is studied. Furthermore, the study of specific absorption rate for the proposed configuration is performed. Finally, the proposed WPT system is designed and experimentally verified with and without metasurface. The experimental result confirms a significant amount of improvement in power transfer efficiency due to the integration of metasurface.

This article presents a technique to enhance the broadside gain of a CPW fed slot antenna using a single layer metamaterial (MTM) superstrate. A finite array of 3× 3 ring unit cell has been designed on both sides of a dielectric substrate to form the MTM superstrate. The gain enhancement is obtained using the zero‐index property of the metamaterial. The broadside gain enhancement for the proposed antenna is 7.4 dB more in comparison to that of the reference slot antenna. The proposed MTM superstrate loaded antenna provides a minimum overall thickness in the context of using ZIM superstrate for gain enhancement of antennas reported in earlier literatures. The overall thickness of the MTM loaded antenna is 0.13λ0, where λ0 is the free‐space wavelength at the resonance frequency of the antenna. Also, a high efficiency of about 93.2% is obtained in this case. The loading of the MTM superstrate produces a minimal effect on the cross polarization performance of the proposed slot antenna.

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