| EBG (Electromagnetic band gap) are artificial periodic structures that can be madeby metallic or dielectric elements. They have many different structures. EBG structureshave frequency band-gap and phase band-gap, they are usually used to control thepropagation of electromagnetic wave in a certain frequency band. In recent years, EBGstructures are widely used in the design of microwave elements and antennas, especiallyin the design of microstrip antenna, a better performance and some new characteristicsof the traditional microstrip antenna can be get when we combine the antenna and theEBG structures together properly.In this dissertation, the details of the frequency band-gap and the phase band-gapare presented and discussed, respectively. Some applications that the EBG structures areused in the design of microstrip antenna are also given. Firstly, the theory and thesimulation models which are used to analyze the two band-gaps of the EBG structureare introduced. Secondly, based on the simulation models mentioned above, thefrequency band-gap of the mushroom-like EBG structure is discussed, for further study,a novel compact EBG structure is simulated and measured, the effect of themushroom-like EBG structure on suppressing the mutual coupling between two PIFAantennas is discussed as well. Thirdly, a variety of planar EBG structures are simulatedwith the simulation model mentioned above, a relationship between the phase band-gapand the structural parameters of the planar EBG structure is get, and then, a circularpolarization antenna and a dual-band low profile antenna are designed. |
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