Design of Flexible Dual-Band Tree Fractal Antenna for Wearable Applications

Abstract

A dual-band flexible monopole antenna for wearable applications is presented. The antenna structure is built based on tree-shaped fractal geometry. The suggested antenna is printed on Rogers RT5870, a semi-flexible material with a relative dielectric constant and loss tangent of 2.33 and 0.0012, respectively. According to the results, the proposed antenna achieves dual impedance bandwidth ranging from 1.72 to 1.88 GHz for the lower band and 5.1 to 5.33 GHz for the upper band. The simulated results show that the fractional impedance bandwidths and realized gains of the antenna are 8.9/4.8% and 1.47/5.67 dBi for the 1.81/5.2 GHz, respectively. The antenna's performance under various bending scenarios has also been demonstrated at both resonant frequencies. The overall size of the proposed antenna is about 45 × 41 × 0.25 mm 3 . The antenna shows good performance to be a candidate for wearable applications.