Design and Analysis of Fractal Monopole Antennas for Multiband Wireless Applications

Abstract

In this report three antenna designs using fractal geometry have been proposed. Fractal is a concept which is being employed in patch antenna to have better characteristics than conventional microstrip antenna. In the first design, a Sierpinski fractal antenna is proposed for multiband wireless applications. It consists of three-stage Sierpinski fractal geometry as the radiating element. The proposed antenna has compact dimension of 75×89.5×1.5 mm3. The multiband characteristic for a return loss less than 10dB is achieved. The model is applied to predict the behavior of fractal antenna when the height of the antenna is changed. The proposed antenna is considered a good candidate for Multiband Wireless applications. In the second proposal, a Sierpinski Carpet fractal antenna is proposed for multiband wireless applications. It consists of two-stage Sierpinski Carpet fractal geometry as the radiating element. The proposed antenna has compact dimension of 59.06×47.16×1.6 mm3. The multiband characteristic for a return loss less than 10dB is achieved. The major advantage of Sierpinski Carpet antenna is, it exhibits high self-similarity and symmetry. In the third proposal, multiband Koch curve antenna with fractal concept is presented. It consists of two-stage Koch curve as the radiating element. The proposed antenna is a compact dimension of 88×88×1.6 mm3. The multiband characteristic for a return loss less than 10dB is achieved. The proposed design is appropriate for mobile communication systems. CST Microwave Studio Suite 2012 is used to simulate these antennas. All the proposed antennas are fabricated on FR4 substrate of relative permittivity of 4.4 and height 1.6mm has been used.