Research On High Precision Navigation Antenna With Fractal

The application of satellite navigation system is more and more widely. As an important part of the navigation system, the performance of the navigation antenna directly affects the quality of the signal transmission efficiency and precision. The antenna is generally used in microstrip antenna or helical antenna. Among of them, the microstrip antenna is the most widely used. But the disadvantages of microstrip antenna is the narrow bandwidth, low gain and easy to excite the surface wave etc. The self similarity and space filling of the fractal can reduce the size of microstrip antennas, and increase the bandwidth of the microstrip antennas. The electromagnetic band gap structure can reduce the surface wave of the navigation antenna to achieve the aim of increasing the radiation efficiency of the microstrip antenna. Therefore, it can be used to optimize the performance of the navigation antenna by the combination of fractal curve and EBG structure. The design of the navigation antenna is a fractal based on EBG antenna.First of all, the paper describes the basic radiation mechanism of the microstrip antenna, analysis method and its common feed mode, and also describes the 3 common fractal structure. They lay a solid foundation for the fractal structure of the antenna design.Secondly, it is the description of EBG structure, and the application of EBG structure in the design of the antenna. The HFSS 13 is used to simulate a EBG structure, and the Sierpinski fractal structure is used to analyze the influence of the fractal structure on the electromagnetic band gap structure.Then, the EBG structure of the Sierpinski fractal curve boundary is applied to the design of the navigation antenna. The effects of the EBG structure are analyzed on the return loss, gain and directivity of the antenna.Finally, A EBG structure based on Koch fractal curve is designed, and the frequency gap characteristics of EBG structure is analyzed. At the same time, the Koch antenna is combined with the EBG structure, and the basic performance of the fractal antenna is analyzed based on the fractal EBG structure. The EBG microstrip antenna with Koch curve boundary is processed, and the simulation results are compared with the measured results. Comparing and analyzing two kinds of fractal structure of the antennas.