Design and bending analysis of wearable antenna with DGS based on PDMS substrate

In the realm of health monitoring systems, wearable antennas play a highly important role in facilitating global monitoring and seamless communication. This paper focuses on a wearable antenna specifically designed for the 5.8 GHz ISM band. Built on ε = 2.65 flexible Polydimethylsiloxane (PDMS) substrate, the antenna has a 9.5 mm circular patch with a star shaped slot, fed by Coplanar waveguide (CPW) for effective power transfer and impedance matching. PDMS, offering adaptability to bending while maintaining performance integrity, surpassing other substrates considered. The antenna measures 37.5 mm x 37.5 mm with 6 x 6 periodic array of Defected Ground Structure (DGS). The antenna achieves 1.2 GHz Bandwidth with an impressive 4.88 dB gain and 7.11 dB directivity. In order to ensure user safety and reliability, focus is on minimizing Specific absorption rate (SAR) below 1.6 W/Kg. The antenna simulated using CST microwave studio, and then fabricated demonstrates excellent efficiency.