Design of compact size dual-band smartwatch antenna for biomedical applications

This paper presents a compact size dual-band antenna that can be perfectly integrated into the smartwatch frame. The proposed antenna operates at 2.45 GHz and 5.8 GHz ISM bands and designed on a semi-flexible material of RT/duroid 5880 (εr = 2.2, tanδ = 0.0009) with an overall dimension of 28.5 mm × 19 mm × 1.575 mm. The final design provides a peak gain of 1.8 dB and 3.8 dB and a −10 dB impedance bandwidths of 350 MHz and 570 MHz at 2.4 GHz and 5.8 GHz respectively. The antenna is studied in free space and then on-body scenarios. The specific absorption rate (SAR) analysis in the wrist-worn have also been presented, which are under the normal SAR criteria. These features make the proposed antenna a strong candidate for healthcare applications of smartwatches.