Design and Analysis of Fractal antennas

Abstract

This report contains design proposals of three antennas with completely different functionalities. All of the three employ the concept of fractal geometry is designing compact antennas with better performance than Microstrip Patch antennas (MPAs). Fractals are one of the ripest fields of research for antenna design, their greatest merit being their ability to enhance electrical length while having virtually unaltered area and better performance. The first proposal is that of a hybrid fractal employing, two distinct categories of fractals, namely Sierpinski Carpet and Giuseppe Peanu, superimposed with each other to give Narrow-band functionality to the antenna. Resonating in the S-band it comes with a possibility to be employed for WiMAX applications. The second proposal is that of a multi-band fractal which again employs a self-similar iterative design. Carving circles out of squares while maintaining electrical conductivity throughout, the antenna results is multi-band functionality. Resonating at five distinct frequencies within the range of 3 GHz to 12 GHz, it has great scope of being employed for the applications that are possible within this range. The third proposal is that of an Ultra Wide band antenna whose fabrication gas also been carried out. Designed by carving hexagonal slots out of a circular patch this is the smallest of the three and optimisation is done using parametric analysis. All simulations are done in CST Microwave Studio. All of them are implemented on the readily available & low cost FR4 substrate of Er= 4.4.Antenna characteristics like radiation pattern and gain are analysed through simulations.