Wearable and Flexible Antenna for Smart Health Care and IoT Networks

The study presents the design of a compact flexible antenna optimized for modern wireless communication applications. The antenna structure comprises a hexagonal radiating patch integrated with a narrow feed line, all fabricated on a flexible substrate with overall dimensions of 80 mm × 70 mm. The radiating patch, having a side length of approximately 19.80 mm, is centrally positioned and geometrically optimized to enhance bandwidth and radiation efficiency. The feed line, with a width of 2.00 mm and a length extending 22.85 mm from the patch, ensures proper impedance matching. The antenna operates at a resonant frequency of approximately 2.45 GHz, making it suitable for applications in the S-band of wireless communications. The estimated bandwidth is approximately 289 MHz (~8.5% fractional bandwidth), and the expected gain is around 4.5 dBi, demonstrating efficient radiation performance. The design utilizes a low-profile, conformal layout ideal for integration into wearable and embedded systems where flexibility, compactness, and reliability under mechanical deformation are essential. Also, the simulated and measured S11 values at 2.45 GHz closely align, with a minimal deviation of about 1.5 dB. This confirms excellent impedance matching and validates the antenna's performance for S-band applications. The design has good manufacturing tolerance, meaning small variations during fabrication do not significantly affect the antenna’s performance, ensuring consistent and reliable operation across different prototypes.