Abstract
Herein, a novel double-inverse E-structured resonator metamaterial (MTM) surrounded by splitring resonators (SRRs) is introduced and proposed. The proposed MTM has working frequency ranges of 1.62 - 1.79 GHz, 2.08 - 2.21 GHz, 4.39 - 4.99 GHz, and 5.65 - 6.09 GHz. In addition, the proposed MTM can be applied in digital cellular system uplinks (DCS) (1.736 GHz), earth exploration-satellite communication (EESC) (2.148 GHz), lower band 5G (4.8 GHz), and WiMAX (5.89 GHz) applications. The electromagnetic radiation reduction performance of the proposed MTM is investigated at 900 MHz and 1800 MHz of GSM cellular bands. The Finite Integration Technique (FIT) based on high-frequency electromagnetic software is utilised for the development of design along with a detailed investigation of the MTM properties. The proposed MTM is formed by developing a double-inverse E-structure in the middle surrounded by SRRs. The resonator structure with SRRs is implemented on an epoxy resin FR4 substrate, which has a compact size of 11.11 x 11.11 mm(2). The unit cell has a high effective medium ratio of 14.82. Furthermore, the developed MTM shows a negative refractive index region from 3.124 to 6.98 GHz and double-negative region from 3.94 to 4.57 GHz, 5.26 to 5.49 GHz, and 6.29 to 6.88 GHz. In addition, SAR evaluation is also performed to test the competence of utilising the proposed MTM on modern mobile phones. The MTM has an electromagnetic absorption rate of about 44% and 43% at 900 MHz and 1800 MHz, respectively, for 1g whereas about 43% and 44% at 900 MHz and 1800 MHz, respectively, for 10g. Thus, the performance and characteristics of the developed MTM can be utilised for the above-mentioned applications.