Affiliations: [a] Urjita Electronics Private Limited, Tambaram West, Chennai, Tamil Nadu, India | [b] Department of Engineering Design, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
Correspondence:
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Corresponding author: Dr. Kavitha Arunachalam, Professor, Department of Engineering Design, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600ย 0036, India. Tel.: +91 044 2257 4740; E-mail: [email protected]
Abstract: An electrically thin (0.024๐0) high-impedance surface (HIS) on a magneto-dielectric nanocomposite (NC) is presented as an external shield for wideband absorption of mobile phone radiation. Characterization of the NC and numerical design and analysis of the miniaturized HIS unit cell on NC (0.088๐0โรโ0.088๐0) are presented over 0.85โ6 GHz, where ๐0 is the free space wavelength at the absorber resonant frequency. The absorber performance is assessed using a mobile phone handset at 0.9 and 1.8 GHz Global System for Mobile Communications (GSM) frequencies and 2.4 GHz Wireless Fidelity (WiFi) frequency. Handset specific absorption rate (SAR) measurements with the absorber recorded in head phantom indicated 83, 48 and 71% reduction in peak SAR at 0.9, 1.8 and 2.4 GHz, respectively without significantly affecting the handset radiation characteristics in free space. Simulation results of human head model with the hand showed SAR reduction of 69, 24 and 65% at 0.9, 1.8 and 2.4 GHz, respectively for 1 g SAR. It is concluded that the proposed absorber could be used to lower handset SAR levels and shield mobile communication signals over 0.85โ6 GHz.
Keywords: EM shielding, high impedance surface, mobile phone, nanocomposite, SAR
