Techniques for reducing the SAR in mobile devices by using graphene-type absorbing materials

Given the well documented health effects of electromagnetic radiation on humans, the SAR reduction techniques are becoming increasingly relevant to the industry. However, satisfying the bandwidth, efficiency, size and cost requirements of a low SAR solution for the new mobile terminals remains elusive to-date. This paper presents a method for designing an SAR shield, based on combined use of graphene-type absorbing cards and metal sheets, to reduce the SAR below the allowable limits. Illustrative results for several test examples are presented in order to show how the size and position of the card influences the SAR reduction level, and how we manage to reduce the SAR levels without sacrificing the antenna efficiency significantly.