Design of Koch Fractal Antenna With Defected Ground Structure for S-Band Applications

Abstract

The proposed article presents a wideband characterized antenna with fractal geometry. To improve the impedance bandwidth a second-order iterated Koch fractal curve is incorporated on the lower and upper edges of the main radiator. The operating frequency of the antenna spans from 1.9 GHz to 4.3 GHz. The impedance bandwidth of 77% is achieved due to the implementation of the defected ground structure. The overall geometry configuration is built on a FR4 substrate. The monopole is powered on a line feed attached to the fractal patch with a matched impedance of 50Ω. The dimensional compactness of the proposed fractal antenna measures 0.641λ0 × 0.434λ0 × 0.016λ0 (fr = 3.1 GHz). A maximum realized gain measures to 4 dBi at 4.22 GHz with better X-Pol level and stable radiation characteristics covering the entire operational band adds to the merits of this investigation. Thus, the proposed monopole can be considered suitable for application in the S-band.