volume | PIER Journals

Abstract

This work presents a compact single-band patch antenna designed for Near-Field Communication (NFC) based skin implant applications. The antenna features an inset-fed patch structure on FR-4 substrate and resonates at 2450 MHz. Three techniques are employed to miniaturize the antenna: a shorting pin between the patch and ground, defected ground structure (DGS), and utilization of tissue electrical properties. A polyamide insulator is used to cover the antenna for biocompatibility. Thus, the optimized antenna volume is found to be 6 × 6 × 0.46 mm³, with near-perfect impedance matching of 51.14 + j4.6 Ω. The antenna also offers enhanced impedance bandwidths of 52.24%. Compared to state-of-the-art designs, the proposed antenna exhibits significantly reduced specific absorption rate (SAR) values of 1.32 W/kg and 0.152 W/kg averaged over 1 g and 10 g of tissue, respectively, in compliance with international safety guidelines. The proposed antenna is effectively free from gain limitations due to the inherently short communication range of NFC technology. Finally, the antenna is measured for its return loss ex vivo, and it is found to be in close agreement with the simulation results. Thus, the balanced performance among the compact size, large bandwidth, and very low SAR makes the antenna a strong candidate for NFC based healthcare systems.

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Mr. Emtiaz Ahmed Mainul

Prof. Md. Faruque Hossain