The Application Of Fractal Technology On UWB Antenna And Multiple Frequencies Antenna

Fractal technology have great potential on application of antenna's minimize and multiple frequency & UWB, This paper mainly research on the fractal technology's application on UWB antenna and multiple frequency antenna. Firstly, this paper amply introduces the basic concept and main characteristic of fractal, then lay out several kinds of fractal dimension. And also this paper introduces several fractal structure's iterative functional system.Then, a fractal monopole antenna is proposed and simulated based on the typical fractal antenna– Sierpinski gasket antenna as the prototype. The simulation results demonstrate that this antenna have very wide frequency band and take up smaller space, also the fractal dipole antenna composed of two monopole antenna have steady input impedance about 150? between 0.3GHz and 10GHz, it can be used as UWB antenna. But generally speaking, we use 50? feeding coaxial line, so we need the impedance match net. Moreover, this paper design and simulate two kinds of crown fractal antenna, the simulation also show that these two antennas have very wide frequency band on impedance and pattern.And then, this paper proposes a novel multi-band fractal triangle antenna which develops from the Sierpinski gasket antenna. The antenna consists of nesting triangles with different heights and degrees of the apex angle. Simulated on the commercial software CST MICROWAVE STUDIO?, the antenna shows multi-band characteristic. Three parameters (height of the triangle, apex angular degree of the triangle and the nesting number) are proved to influence the central frequency of the pass bands. Summarized from the impact of these parameters, antenna with three passbands 900MHz, 1.8GHz, 2.4GHz) are designed adjusting these parameters. Furthermore, in order to remove the infinite conductive ground, the symmetrical antenna is discussed and the simulation results indicate that the antennas also have three pass bands with the same central frequencies as well as UWB characteristic in the high frequency range. Thus, the multi-band fractal triangle antenna is a novel antenna with controllable frequency bands and promising application.On the above foundation, two kinds of UWB fractal antenna and multiple frequency antenna are made and tested, the tested results is identical with the simulation results on the whole, and prove fractal antenna have UWB & multiple frequency characteristic.