A Research Of Microstrip Antenna Based On Novel Electromagnetic Materials

Since the founding of new type electromagnetic materials, many scholars carried out a lot of research, proposed many kinds of optimization scheme based on its surface wave band gap and reflection phase band gap have, and has verified the new electromagnetic material has a unique advantage in antenna design. Most of the electromagnetic model is multi parameters, multi-objective, nonlinear problems, which makes using the basic numerical methods for solving it is suffering, but based on Darwin’s evolutionary theory, genetic algorithm can get rid of the practical problems will rely mapping parameters to its individual vector by a proper assessment of individual, the ultimate realization of the parameter optimization, which can well meet the performance requirements. In this thesis, the related research status quo has been analyzed, and analyzed the mushroom type electromagnetic band-gap structure, which is the basics to apply it into the design of the micro strip patch antenna to realize the gain enhancement and the polarization transition.In this thesis, the parameters of the model which is affecting the surface wave band gap has been analyzed, and the model parameter selection also been summarized. In this part, the upper patch of the mushroom type band gap structure is subdivide according to a custom rule, which is amid at using the improved genetic algorithm to optimize the design, and a structure is been designed which has about-9d B transmission coefficient. Adding the structure into the surrounding of the patch, can be well suppress the surface wave and enhance the gain. Through the simulation and measurement, the antenna gain increased by 1.73 dB.In this thesis, the parameters of the model which is affecting the reflection phase band gap has been analyzed, and the model parameter selection also been summarized. In this part, analyses the traditional single band structure to make sure how the parameters influent the reflection phase band gap, and puts forward how to select the parameter to complete the design requirements; Analyses the polarization independent dual band structure to understand how to change the parameter to meet the requirement. For the 2.45 GHz and 5.8GHz bands, a rectangular patch loaded elliptical ring hollowed out structure is been proposed for the first time. Through the simulation and optimization, the 3dB axial ratio bandwidth of the antenna with proposed structure reaches 90 MHz and 180 MHz, realizing converts the dual band linear polarization antenna into a dual band circular polarization antenna.