Specific absorption rate reduction of multi split square ring metamaterial for L- and S-band application

In this paper, a framework for investigation on mobile phone and human head interaction are presented for L-and S-band applications. The proposed compact metamaterial design helps to reduce the Specific Absorption Rate (SAR) value that exposed to the human head. A recent achievement in metamaterial field allows this unusual material widely used in mobile phone applications to enhance the accomplishment and consequently received substantial attention among researchers. Hence, a multi-split square ring metamaterial design developed on a 1.6 mm thick dielectric substrate layer known as Epoxy Resin Fiber (FR-4). Electromagnetic properties of the proposed metamaterial structure were calculated through numerical simulation tool using the Finite Integration Technique (FIT) in Computer Simulation Technology Microwave Studio (CST). A few designs were used to conduct parametric studies with altering the substrate material, design structure, array arrangement and phone distance from the human head. 0.3-4 GHz frequency range was utilized in this simulation, where the proposed design established resonance frequencies precisely at 1.81 (L-band) and 3.79 GHz (S-band). The measured results show the resonance frequencies occurred at 1.82 and 3.72 GHz. Therefore, with a little bit discrepancy between the numerical and measurement results, it made the comparison was largely in agreement. The SAR value shows that a reduction by 36.87% and 45.54% at L- and S-band respectively for averaged over 1 g of tissue volume. While for averaged over 10 g of tissue volume, integrated metamaterial design in mobile phone reduced by 35.29% and 48.36% at L- and S-band respectively.