Application Research Of Several Fractal Technologies On Antenna

As a mathematic tool of modeling natural geometry, fractal theory has been found wide applications in varied fields with great success. Recently it has also been applied to RF(Ratio Frequency) fields, and valuable achievements have been reached.'Fractal'has space filling ability and self-similarity ability.'Fractal'is a recursively generated structure by iterated function systems. It has a fractional dimension and possesses a self-similarity property. The concept of a'fractal'has been applied to antenna design in order to reduce the size of antenna and obtain multi-band frequency operation. Fractal antennas have broad application prospect in military and civil applicationThe application background of'fractal'is introduced and then the thesis summarizes the research status and expatiates'fractal'and'fractal dimension'in detail. Simultaneity, iterated function systems is applied to analyze this transforming process of a few representative'fractal'antennas.Several most basic fractal structures like Koch, Tree and 3/2Curve are chosen to make up antennas. The antennas are simulated by CST MICROWAVE STUDIO? based on the Finite Integral Method. The simulation results are compared to the normal dipole antenna in order to observe the influence of fractal and investigate the effect of antenna miniaturization. The relationship between miniaturization and fractal dimension is researched.The Koch and 3/2Curve fractal unit are applied to Yagi-Uda antenna, the performance like impedance characteristic and radiation pattern is simulated by CST MICROWAVE STUDIO?. The miniaturization effect by fractal unit to the lateral size of the Yagi-Uda antenna is discussed, and introduced the influence to the cross polarization.The suitable tree-like and 3/2Curve fractal symmetrical vibrators are chosen to make up a log- periodic antenna (LPDA), the performance, such as reflectance, input impedance, radiation pattern and gain are also compared with normal log-periodic antenna by CST MICROWAVE STUDIO? simulation, in order to investigate the effect of antenna miniaturization.The application of fractal technology in microstrip antenna is introduced at...