Wearable Circularly Polarized Fractal-Shaped Antenna for Wireless and Defence Applications

Abstract

This paper deals with the novel design and fabrication of Minkowski fractal antenna implanted on textile substrate material. Investigations on the analysis of conventional line-fed microstrip and transformed fractal-shaped patch antennas are performed. Jeans cotton is dielectric substrate material used in this work with permittivity of 1.6 and the thickness of 0.8 mm. Initially, a rigorous analysis is carried out in tuning the inner dimensions and indentation depth of the patch antenna design progressively to obtain the optimized final structure. Outer dimension of the patch with Minkowski fractal shape is 100 mm × 100 mm, which is further implanted on jeans substrate operating at 3.89 GHz single band with obtaining circular polarization (CP). Asymmetric slits cut on either sides of the fractal structure with indentation depth variation is able to excite the orthogonal resonant modes with 90° phase shift. Structures are implemented using 3D CST MW Studio simulator and found that a high gain of 6.89 dBi is obtained at the resonant frequency. Development of this wearable fractal antenna structure poses significant challenge not only in obtaining the desired band of antenna functionality for WLAN, GNSS remote sensing, and defence application, but also in integrating the functionality into wireless wearable systems as a cost-effective solution.