A CPW-Fed Hexagonal Antenna With Fractal Elements For UWB Applications

We propose a coplanar waveguide-fed hexagonal antenna design for ultra wideband applications. The size of the antenna is miniaturized to 25×25×1.588 mm3 and the impedance bandwidth is improved by adding fractal elements at the edges. Parametric analysis of the fractal elements and the impedance behavior is performed to realize the radiation characteristics and bandwidth coverage as required for microwave imaging. The addition of fractal elements introduces multi-resonance at different frequency and covers a large bandwidth of 1.7 GHz–11 GHz respectively. The effect of surface currents in the ground plane reduces the antennas operating bandwidth which is reduced by introducing defective ground structure. The proposed antenna has an average gain of 2.35dB, radiation efficiency of 93% to 96%