Analysis and design of circular fractal antenna array for multiband applications

Abstract

In this paper eight element circular fractal antenna array is designed. The elements of this antenna array are separated by a distance λ/2. FR4 glass epoxy with 4.4 relative permittivity and 1.6 mm thickness is used as substrate material for the design of proposed antenna array. The resonant frequency of the proposed antenna array is taken as 4 GHz. Three iterations of the proposed fractal antenna array are designed and fabricated. It is found that as the iteration number increases, the gain of this array at resonant frequency increases and the beam-width decreases. The effects of various parameters on the performance of antenna array is analyzed using 3D electromagnetic simulator (HFSS) based on FEM method. Proposed fractal antenna array resonates at ten frequencies in the frequency range from 1 to 10 GHz. The values of reflection coefficient and the gain at all the resonant frequencies have acceptable values. The resonant frequency of fractal antenna array is also shifted towards the lower frequency from 3.91 to 3.80 GHz which reduces the size of fractal antenna array by 6% than the conventional antenna array. Proposed fractal antenna array covers the different wireless standards such as Wi-Max (3.5–3.8 GHz), C-band applications (3.8–4.4 GHz and 4.8–5.4 GHz), WLAN (5.15–5.85 GHz), X-band for satellite communication (7.1–7.76 GHz). The simulated and experimental results are found in good agreement with each other.