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Description
The study introduces a compact dual-band antenna designed for wearable applications operating in the 2.45 GHz and 5.8 GHz ISM bands, with an emphasis on low Specific Absorption Rate (SAR) values to ensure user safety. As wireless communication devices proliferate, concerns about the potential carcinogenic risks from electromagnetic radiation have prompted the establishment of SAR limits by regulatory bodies such as the FCC and EU. The proposed antenna is built on a polydimethylsiloxane (PDMS) substrate, known for its flexibility and low dielectric constant, which are ideal for wearable technologies. The antenna incorporates a microstrip feedline with an inverted L-shaped slot for resonance at 5.8 GHz and a U-shaped stub along with a partial ground plane for resonance at 2.45 GHz. Additional meandered line structures are used to fine-tune the antenna's performance. The antenna exhibits dual-band operation with impedance bandwidths of 2.37–2.507 GHz and 5.68–5.85 GHz, providing gains of up to 1.35 dB and 2.7 dB, respectively. When analyzed for SAR, the antenna meets the safety limits set by U.S. and EU regulations, with values of 1.12 W/kg at 2.45 GHz and 0.277 W/kg at 5.8 GHz for the 1g FCC standard. The antenna's performance remains stable under conformal conditions, with minor deviations in return loss. These features make the antenna a promising candidate for wearable devices operating in the ISM bands.
