shahram hedayati

  Fractal geometries are widely used in radiating systems and even microwave devices to benefit from their interesting properties. Application of fractal geometries to the design of antennas leads to their miniaturization and multi-band characteristics. Since the generation of fractal configurations have an iterative procedure, then they can achieve long linear dimensions and high surface areas in a limited volume. However, in this project we present the novel structures and application of those in the micro strip antenna and then we compare the miniaturization performance of proposed fractals antenna with that of other fractals. First proposed structure in this thesis is Giusepe Peano fractal geometry, which realizes its miniaturization while maintaining its gain and bandwidth. These novel fractal geometries used for different micro strip antennas and we survey characteristics of these . In another section of this thesis the combined fractal proposed, that these structures are common fractal that combined together for approach higher degree of freedom that further miniaturization of antenna may be achieved. In another section of this project we proposed the novel geometries for monopole fractal antennas, in this section we introduced Lebesgue fractal geometries and use of this for design of multi-band antennas with circular polarization in all of the bands. In final section, we use wavelet basis functions in the method of moment and present novel algorithm for selection dominant basis functions and then we used MLMDA method in method of moment, required storage memory and cpu time reduced with respect to the common method of moment.

  defence date:2010-07-06 Time: 15

  Place: