Design of Polymer Based Wearable Antenna for Biomedical Applications

Demand for flexible wearable antenna has increased in recent times. Various methods and design were proposed to minimize and improve the antenna performance based on gain, efficiency, S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>. This article presents a flexible wearable antenna for biomedical applications resonating at 2.4-2.48 GHz. Designed antenna uses Polymer based flexible material polyimide (є<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf> = 3.5, loss tangent =0.0001) as substrate. Size of the antenna is 28 x 20 x 1 (all in mm). Patch is etched with rectangular slots and resonant frequency can be decreased by reducing the ground plane. Slot dimensions are varied to obtain the desired antenna design. The proposed antenna operates at 2.417 GHz with 2.03 dBi gain, 1.02 VSWR and 2.250 dBi directivity. 95% radiation efficiency is achieved by the proposed antenna. Specific Absorption Rate (SAR) is measured for two-layer phantom model with different air gaps and three-layer phantom model. SAR value obtained is well behind the maximum acceptable value for two- layer phantom model. CST studio is used for simulating the designed antenna and the simulation output shows that it can be a good option for wearable biomedical device.